Systematization of the Knowledge of Relevant Signals in Evaluating

the Surf Zone

Proficiency in Positioning in the Surf Zone Lineup and in Wave Catching

João Miguel Antunes Brogueira and César José Duarte Peixoto

Faculdade de Motricidade Humana, Universidade Técnica de Lisboa, Lisboa, Portugal

Keywords: Safety, Coastal Currents, Surf, Systematics, Wave Knowledge, Lineup, Patterns.

Abstract: Regarding the beach safety of surf zone users, this study aims to systematize the “Wave Knowledge” of the

most efficient lifeguards, the surfing masters, by classifying the indicators relevant for recognizing spacial

and temporal patterns and risk factors. This is evidenced by the proficiency in motor tasks essential both to

the sport and rescuing in the surf zone: positioning in the lineup, catching waves/ returning to shore (when

“Wave judgement” is needed). We start by reviewing the literature from Surf Sciences, followed by an

analysis of manuals of Surfing as a sport. Then we researched the prospective procedures of experts in

extreme surf conditions and observed behaviour of top surfers in competition, to put up a classification of

the visual signs used (sea and swell, wind, tide, seabed configuration, currents, and details of breaking

waves’ forms). Based on the acquired data, we built a Questionnaire to rank the “relative importance of the

signals”, which surveyed 11 surf national champions/ coaches (male/female practitioners with over 15

years’ experience). Results show that experienced surfers evaluate all elements of the “waves-currents

system”, although the location, type and intensity of maritime currents (except under conditions of small

waves), and the swell characteristics (angle of arrival to coast, height, period) stand out as the most

important. The importance of the signals varies according to the wave height and the wave break types. The

respondents also attend configuration of seabed and coast profile in their evaluation. As for the surf quality,

they consider the characteristics of the coastal wind and temporal characteristics of the tides. For the

strength of the surf and the take-off point, the focus is on sections and wave face profiles (slope, thickness).

1 INTRODUCTION

1.1 Symposium Technology in Surfing

Paper made for TechSurf, Congress “Sports Science

Research and Technology Support icSPORTS2013”,

21 Sept Portugal. Master thesis presented in

Faculdade de Motricidade Humana, 21 July 2011.

May it contribute “For others may live”, motto

that my father flew in FAP. Professor Peixoto made

it possible. Greetings to the expert surfers inquired.

Mother, thank you. Love, beautiful Cecília. To

Joana: love you, dearest daughter, fight for dignity!

Figure 1: Observe, research, systematize, teach, compete.

1.2 Foreword: Unacceptable Mass

Drownings in Surf Bathing

In this study we approached the problem of

safeguarding human life when bathing/ swimming in

our Portuguese sea, from the perspective of the most

efficient lifeguard – the very experienced and

informed surfer, used to big waves, with exceptional

fitness. “[Hawaiian, North Pacific] Surfers made the

best lifeguards because they have experienced first-

hand how powerful the ocean can be. They also

knew the most about its many variables, including

waves, wind conditions, currents, rip tides, channels

and shore breaks”; “people who understand the

ocean and are not afraid of it” (Coleman, 2001). In

Oceanic coastline, where all environment elements

are commonly present with uncontrollable forces

(and occasionally brutal, by conjunction of variables

that to the layman tourist look ordinary), these wave

runners possess a practical knowledge about the

Ocean’s wave-currents dynamics in the wave

104

Brogueira, J. and Peixoto, C..

Systematization of the Knowledge of Relevant Signals in Evaluating the Surf Zone - Proﬁciency in Positioning in the Surf Zone Lineup and in Wave Catching.

In Proceedings of the 3rd International Congress on Sport Sciences Research and Technology Support (icSPORTS 2015), pages 104-118

ISBN: 978-989-758-159-5

breaking coastal zones (“surf zones”), which is

fundamental in Beach Safety and in Sea Rescue. In

Portugal [North Atlantic] the “surfer lifeguard”

brought new knowledge and practices that were

applied from 1973 in “new methods and equipment”

in rescue practices. This resulted in no more

drownings in beaches where it was frequent. “The

choice of lifeguards surfers is an added value to any

beach on the Atlantic coast”, “a sea with strength

and currents, unpredictable and where we find

changes in the currents, the size and strength of the

waves in just a few hours” (Rocha, 2008).

These experienced sporting watermen,

“extremely proficient ocean swimmer and surfer

[…] who can make informed decisions and

predetermine the level of risk they will face”

(Guisado, 2003), “know how to identify, to

anticipate and to explain the risks” (Coleman, 2001),

are the most capable and competent rescuers (Surf

Life Saving Association of Australia, 1975). In these

conditions, the understanding of the phenomena, a

good knowledge of surf conditions, is vitally

important to all surfers (Orbelian, 1982) (Somers,

1988) (Lowdon, 1988) (Noll and Gabbard, 1989)

(SLSAA, 1974) (Collins, 1992) (Dupouey, 1997)

(Jenkins, 1993) (Butt, 2002) (Colburn et al, 2002)

(Slater & Borte, 2003). Aware of the importance of

“playing by the ocean’s rules”, expert surfers pass

on this Wave Knowledge and “sea reading” ability,

in each surf spot, to their infants and local peer

group (Carroll, 1994) (Young, 2003) (Hall, 2004)

(Rocha, 2008) (Pereira, 2001) (Jarvis, 2004). “The

best surfers learn from the very best, growing up

immersed in a multi-generational culture of

complete ocean awareness” (Slater, 2005).

Among beach users, this “awareness” is

misunderstood; these “secrets of the sea” are

complex and not obvious. The urban common sense

and the general teachings of classic mechanics are

inappropriate in the Portuguese coast bathing zones,

a chaotic system with ocean waves and currents.

Here wave heights remain above 1 meter for 95% of

the year, and above 4 m for 5% of the year (Instituto

de Meteorologia, 2007). Moreover, some natural

environments, like high-mountain, rafting waters,

scuba-diving depths, and surf zones, require being

aware that human technology and intellect cannot

domesticate the forces in presence. Nature, although

accessible in artificial coastal zones (of banal

urbanization and coastal compression), is wild.

When facing a challenge with a danger level beyond

one’s competences (knowledge, skills, aptitudes),

there must be full consciousness that, by insisting,

the experience may become adverse or even

disastrous and tragic (Swarbrooke, 2003). In this

leisure practice of surf bathing, it is fundamental,

vital, to be informed and aware of the risks, being

able to identify the intensity and dynamics of

nature’s forces present, as well as the hazardous

places (Surf Life Saving Association of Australia,

1974). The flat water swimming skills and

swimmers’ physical fitness are not enough to ensure

the ability to return to the coast, as the Portuguese

Lifeguard Manual advises (Pereira, 2001).

1.3 Surfing, Best Surfer, Surf Master

In sporting terminology the correct and officially

admitted vocabulary is necessary, as it allows to

convey precisely all the technical elements. The

words must be accurate to avoid misunderstandings

from practitioners and technicians, “or even in the

translation of a text” (Peixoto, 1993). A section is

dedicated to operational definitions to define the

problem, in the full text of the thesis. All expressions

or terms in any form considered technical (i.e. not

generally known) appearing in the problem are

defined, as the investigator considers it. Any

ambiguous term, or a special meaning in the context

of this study, albeit in common use, are clarified.

“Surfing breaks have great social and economic

value for coastal communities. In order to preserve

and enhance these resources, a common language is

needed that will bridge the gap between the

colloquial slang of surfers and the technical

language of scientists and policy makers. This

language is the science of surfing waves and surfing

breaks” (Scarfe & al, 2003).

This short paper does not include the revisions of

the subjects Oceanography, Meteorology,

Hydrography and computer Modelling concepts

regarding physical wave elements, maritime wave

formation and propagation, winds, sea ripples and

fetch, the phenomena of offshore swell characteristic

properties (reflection, refraction, diffraction,

interference) and coastal waves characteristic

properties (shoaling, refraction, diffraction), coastal

processes, wave-currents system and equilibrium

beach profiles, tide elements, seabed, seasonal beach

profiles, erosion and coastline, categorized types of

surfing breaks, main surfing wave parameters

(“surfability”), artificial reef breaks, maritime

agitation characteristics in the Portuguese coast, and

temporal conjunction effects (like coastal jets,

rogues, exceptional wave sets, onshore wind setup,

storm-surge, spring tides, current effects). They can

be consulted in the thesis.

Systematization of the Knowledge of Relevant Signals in Evaluating the Surf Zone - Proﬁciency in Positioning in the Surf Zone Lineup and

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105

1.3.1 True Surfing

Surf in the English language designates the maritime

surface waves breaking in coastal zone (breakers). In

Portuguese Surf designates the Surfing sport itself,

Surfe is used in Brazilian.

The “To surf” definition must be considered,

since it concerns the essence of the proficiency

studied. This is the sport of surfing (he’e nalu

(wave-sliding), surf-bathing, Hawaiian sport of surf

playing, swell driving, surf riding, surf board

swimming, wave-riding, surfing). “Surfing is the

sport of riding across the face of a wave while

standing on a specialized board” (Orbelian, 1982)

“The art of standing up while riding diagonally

across a wave front” (Finney & Houston, 1996);

“Travel on the wave […] slide on the wall of the

wave, […] towards the beach” (Moreira, 2007).

Therefore, it should be clear that any Surfer is

always referring to a wave face ride

(Finney&Houston, 1996) (Young, 1983) (Pukui,

2003) (Warshaw, 2005), never to a straight-off ride

on the white-water wash of the collapsed wave. We

also refer to the judging rules: “The contestant that

systematically chooses the waves that close out

should be penalized (in the score) for having choice

and acting against the spirit of surfing” (Jonet,

1989). Catching a wave means a controlled descent

through turns, travelling/cutting the wall of wave,

i.e. in nautical terms manoeuvring. This greatly

reduces the location of quality peaks, and the

opportunities for surfing (good waves available from

the whole sets).

It has huge implications on proficiency, for the

outside must be reached, and the lineup must be

read, to find the first take-off zone (the point where

the swell collapses to become surf): they have to

deal with the currents and the possibility of not

being able to catch waves (i.e., returning to shore!).

Very strong indignation was caused by tourists

bragging of being surfers when poorly riding in

white-water from small broken waves, while they

understood nothing of the Ocean (Crowe, 2002); so

in 1911 native Hawaiians revived the practice of

“true surfing”, in the organized form of a the Hui

Nalu club (Finney&Houston, 1996) (Hall, 2004).

1.3.2 Surf Master’s Expertise

“A masterful surfer is a product of (usually) around

20 years of concerted, directed effort, a hundred

different surf spots, several hundred boards and a

couple of hundred thousand waves” (Carroll, 1994).

Mastery in surfing is a result of refining the general

knowledge of the surf dynamics; it derives from

“local wave knowledge”; and it allows efficiency

through conjunction to surf energies. “All beaches

are different and each surfer is the individual able to

realize the surrounding situation” (Amaro, 1989).

This “experience and expertise to handle the big

surf” (Coleman, 2001), or “most masterful surfer"

(Melekian, 2004), differs from the daily tricks

performance from the “best surfer/ most skilful”.

Surf Masters are the experts who are relevant to

observe and question in order to record their

procedures in surf reading, so that we have a chance

to organise this wave knowledge. “Every surf spot

will have its own characteristic wave, which will

change according to tide, swell, and wind”

(Orbelian, 1982). “[D]ominance is ability

supplemented by knowledge. Knowledge developed

over time. Knowledge acquired by consistency.”

(Melekian, 2004).

2 OBJECTIVES

We aim to classify and systematize the expert

surfer’s wave knowledge, “using objective,

accessible, exact, concise sport terminology”

(Peixoto, 1993).

The goal is to understand and organise the surfing

master’s knowledge about the surf and currents, so

that information for spacial and temporal pattern

recognition at sea, surf and currents may become

public, having a practical application for Beach

Safety.

2.1 Starting Question and Problem

In order to fit the line of investigation, an initial,

very broad, question arose to review the knowledge

already produced about the various areas of study:

‘It is possible to systematize the knowledge about

the surf zone that defines surfer's proficiency,

whether in sports practice or in sea rescuing?’

The Problem consists simply in an expansion of

the study title (‘Surf Masters: Systematization of the

knowledge of relevant signals in evaluating the surf

zone’) presented as this general statement: ‘the goal/

purpose of this research is human life safeguard,

systematizing the practical surf zone knowledge that

defines a surfer’s proficiency, knowledge used to

evaluate the surf conditions, find and catch the surf,

by using the relevant visual signals from the waves-

currents system’. We question the most efficient

lifeguards in beaches with surf, and analyse the

motor tasks essential both to the sport and surf

rescuing.

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“Wave judgement is the most difficult aspect of

surfing to master. It takes years to accumulate the

experience needed to deal with the multitude of

situations the sea is capable of” (Orbelian, 1982).

We research into the possibility to systematize the

surfer’s “wave knowledge” about wave-currents

dynamics in the surf zone by using a classification of

the relevant signals from the coastal process

(dynamic, non-linear). For risk assessment, the game

rules, the context evaluation, the “ocean reading”

ability, the “wave knowledge” skills: “Which are

visual cues that enable evaluating the variables

specifiers of the characteristics of waves and

currents, and especially which are relevant to the

surfing conditions at hand?”.

“Most accomplished big wave riders are in their

thirties. It takes a long time to build the experience

and, mainly, the judgement required to ride big

waves” (Ricky Grigg, in Noll & Gabbard, 1989).

The associated problem is the “wave judgement”,

skill necessary to catch waves: “Which are the

relevant signals about the surf shape characteristics,

to evaluate the plan where the breaking wave passes,

and its profile and strengths?”.

2.2 Pertinence and Complexity

“The area of the coast where the waves break is one

of the most difficult maritime regions to study due to

the high intensity and non-linearity of the waves and

currents. Beyond the scientific interest motivated by

open issues, it is a strip that we need to understand,

that it is crucial to coastal erosion, dissipating wave

energy, coastal works, sediment transport, pollutant

dispersion, surfing and safety of swimmers and

boats” (Bicudo, 2007).

The task of reading and understanding the ocean

waves (“observe, analyse, decode, compare and

deduce”), is ambitious, “somewhat foolish for the

extreme complexity involved” (Dupouey, 1997). We

pursue an original task of explaining the reading of

the signals picked up on the ocean coastal waves and

currents dynamics; parameterizing objectively the

essence of a shared collective consciousness (Slater,

2005). And by doing it in a maritime population that

share a feeling of competition among themselves,

cohesive and used to live in uncertainty and danger

(Moreira, 1987), for whom any spreading of the

“local wave knowledge” (such as surf-travel

guidebooks, surf-reports, surf-trip diaries) is

“regarded by many surfers as nothing less than

heretical, as it revealed in just a few short pages

information that had taken local surfers years to

accumulate” (Warshaw, 2005). Even in lifeguard

courses, it is advised to have “practical experience in

surfing” in order to acquire this “knowledge and

experience from spending many hours in surfing”,

and “discussion with old hands” is also suggested

(Surf Life Saving Association of Australia, 1975). In

Portuguese Lifeguard Manual (Instituto de Socorros

a Náufragos) this complex knowledge is condensed

in 7 pages of elementary information. This

divulgation of information to the public was already

urgent in 1970, when the beach surveillance was

reinforced, as well as the training and divulgation to

prevent sea accidents (Pereira, 2001). Today, it is

still up to the bather’s experience the deadly trial and

error evaluation of “environmental conditions”.

2.3 Hypotheses

Hypotheses are the answers to the starting question

that the Problem in study raises, i.e. plausible

predictions as result of the literature research. In

Oceanography, a “systematic and considered

approach” is required for discovery given that the

ocean (climate) system “can be characterized by

modes that can be thought of as naturally occurring

patterns of variability, with each pattern exhibiting

unique spatial characteristics but typically vague

temporal characteristics”: “the knowledge about

patterns and processes in the ocean results from the

observations of relevant parameters” (Anderson,

2003). And “Surfing is a feeling for the sea, a

combination of love, knowledge, respect, fear –

instinctive perception gained through repetitive

contact” (Wardy, in George, 2001).

“Observation is an essential prerequisite to

identifying and understanding the complex patterns

and trends of variability in the ocean, complemented

by hypothesis-driven studies focusing on cause and

effect [with non-linear relations in these systems].

The study of these patterns, identified by

experienced scientists, starts in observation, then

using intuition (inductive method), requires the right

questions, leads to “suggestions of possible

interconnexions between unrelated facts, in the

complexity and subtle relations of patterns and

processes” (Tomczak, 2002). Intuition from

experience is expressed in the words of the “King of

Pipeline” (Jenkins, 1991): “One of the things you

learn riding the waves consistently is your ability to

find a pattern, or a rhythm, in the randomness of the

ocean” (Stewart, 2011).

Systematization of the Knowledge of Relevant Signals in Evaluating the Surf Zone - Proﬁciency in Positioning in the Surf Zone Lineup and

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2.3.1 Hypothesis 1: Indicators for

Perception of Practice Conditions

H#1: For perception of practice conditions, expert

surfers use indicators of sea conditions regarding

specifier variables of coastal morphology,

bathymetry, breaking waves–currents system, tides,

and local winds.

2.3.2 Hypothesis 2: Valuation of Indicators

According to Practice Conditions

H#2: Expert surfers value different indicators

according to practice conditions: wave heights and

type of surfbreak (seabed sedimentary or

permanent).

2.3.3 Hypothesis 3: Indicators for

Perception of Wave Profile

H#3: Expert surfers use indicators of ramp shape

and edge shape for perception of the formation,

speed and strength of breaking wave profiles.

2.3.4 Hypothesis 4: Indicators for

Perception of Wave Plan

H#4: Expert surfers use indicators of wave wall

shape for perception of the formation, speed and

strength of breaking wave plan.

3 LITERATURE RESEARCH

There are no previous studies on visual signs for risk

assessment on open sea bathing zones. For a

classification of Wave Knowledge, we start the

compilation with the analysis of the fundamental

concepts of Coastal Oceanography, coastal process

factors, wave-currents system dynamics, ocean wave

elements and properties, wave properties at the coast

and surf zone characteristics. We researched coastal

engineering studies in wave-currents interaction, for

the conjunction occurrences. We attend into nautical

scales for wind and sea strength. We narrowed the

research by considering the characteristic parameters

used in computer modelling for wave forecasting

and wave simulation models. We collected the

relevant variable specifiers to monitor wind, sea and

surf conditions and its evolution in space and time,

data available in real-time measurements from

systematized sources, like data for the evaluation of

surf conditions at the beaches, in the scope of

Maritime Safety. From Portuguese Navy’s

Hydrographic Institute, and Meteorology Institute,

we obtained the Characterization of the Climate, and

Maritime Agitation, on the Portuguese coast, to

know the seasonal sea typical conditions, in typical

situations. In order to understand the sediment

movement in sandy beaches, we checked coastal

erosion processes and seasonal beach profiles.

Determinant clues come from recent Surf

Science studies, by surfers, not only on Surf

Forecast and “surf spot guides”, but now on wave

types and profiles, surf break types and ocean

bottom topography and bathymetry (scientific

investigation held also in Portuguese relevant surf

spots), “surfability parameters” (Bicudo, 2007) and

breaking waves conditionings (also for Portuguese

artificial surf reefs).

Exploratory readings from publications of

surfing culture helped our route, due to the

complexity of order the phenomena in this dynamic

and chaotic environment, with the immense

variability of conditions it may present. First we

defined the components of a Surf Master (ability,

knowledge of surf conditions, experience). Then

found examples of intergenerational retransmission

of local surf spot knowledge. From literature

research of surfing master pioneers in extreme

surfing, the prospective procedures on their lineup

search are picked. We look at sailor’s navigation

history/ manuals for knowledge of piloting

techniques when near unknown seashores. Also, in a

method triangulation, to strengthen this exploratory

study, using observation in competition, we

researched the actions that distinguish surfing

champions, the surf lining up (at the primary take-

off zone) and the (best) wave catching.

4 MODEL OF INSTRUMENT

INTERACTION

This section is dedicated to the sport systematics

approach “Model for the Interaction of Instruments”

(Peixoto&Ferreira, 1994) (Peixoto, 1997) (Peixoto&

Moreira, 1999) (Peixoto, 2000) (Moreira, 2007).

Since our object of study is the sport of surfing,

in the perceptual component of the practitioners, it is

not possible to use the hierarchy of variables

specifiers of natural elements, ranking it for

systematization. Therefore we use the term

Classification, “the act/ process of classifying each

variable in itself” and also “the possible relationship

between the [...] variables” (Fernandes, 2000), using

grids to order the phenomena, in a methodical way

to showcase the different components of this system.

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“Analysing sports performance is no more than

structuring the different variables/ instruments,

clearly and objectively as a resource for effectively

improving the technical intervention” (Peixoto,

2000).

The full text of the thesis, available online at the

University Repository, contains the classification

tables, created for the Wave Knowledge

Classification (signals used for evaluating surf

conditions), and the Wave Judgement Classification

(signals used for evaluating breaking waves

components – form, speed and strength). These

classifications were the basis of the survey for the

experimental methodology of this research.

It also includes the analysis of the motor tasks

essential to surfing practice (and to Surf Rescuing),

directly related to the wave knowledge: “Surf lineup

positioning” and “Wave catching” – identifying the

primary wave take-off area, navigating to lineup,

choosing the wave, defining the entry point, carrying

out the final approach and starting the slide/fall on

the wave face. Furthermore, we present a breakdown

of the “Take-off technique”, and a table of

“Classification of Surfing Manoeuvres”, organised

by level of difficulty and by the part of wave face

where it is performed.

5 EXPERIMENTAL

METHODOLOGY

This master thesis researches Ocean reading skills.

With the goal to present this knowledge organised

and quantified, based on information gathered in

literature research, indicators were systematized for

evaluation of practice conditions and recognizing

patterns and trends (padrões e tendências, in

Portuguese) at the coastal process and on the surf.

For testing this Classification through a research

instrument, namely to gather information by

inquiring a group representative of the population in

study – the best Portuguese surfers –, we created a

Questionnaire, designated “Relative valuing, by

expert practitioners, of signals in the surf zone for

the optimization of wave catching” (“Valorização

relativa, por praticantes peritos, de sinais na zona

de surf para a optimização da entrada na onda”, in

Portuguese). The design was completed in

December 2007, and the implementation took place

in January 2008.

5.1 Validity and Guarantee of the

Instruments

The questionnaire was subject to validation, through

expert opinion test, with the collaboration of

Professor Bicudo, also a surfer with 15+ years of

experience and teacher of surf forecast for surf

coaches.

The theoretical grounding, based on the

classification made, followed strict guidelines on

information sources due to the pioneering and

exploratory character of this research. In the

literature review, information from the essential

parameters of coastal Oceanography and

Meteorology was gathered, such as the ones

monitored for the navy institutes, used for modelling

surf forecasts, as well the ones referred to in surf

modelling studies. As regards journalistic sources

(surf magazines), we considered articles resulting

from fundamented investigation, such as

dictionaries, historical reviews, and biographies. For

publications, books about surfing, only used author’s

considerations after a critical analysis, searching the

original sources and writers known for excelling as

surfers, especially when they become academics and

research on studies in the areas of Oceanography,

Sports Training, History, Anthropology, Sociology

or articles about technique and strategies for success.

The closed options questionnaires are objective

and require less effort from the respondent. Given

the length of the questions, it was the best option; it

also facilitates the processing and analysis of

information by requiring less time. A limitation of

the application of this type of questionnaire is that it

makes answering easier to an individual who did not

know or have difficulty in responding to a particular

issue.

5.2 Population Inquired: National

Surfing Champions

The study required a sample of top Portuguese

expert surfers, that meet this criteria of very relevant

verifiable curriculum in surfing: 1) surfing

experience (at least 15 years of practice); 2) elite

surfer with exceptional results in competition

(achievement of national surf champion title in adult

category); or 2) to be a surf coaches master

(teacher). Since the official competitions began in

1986, the limited universe of the population justifies

considering that respondents are sufficient for valid

general conclusions.

Men and Women are considered alike; they must

meet criteria 1) and 2). A total of 11 elite surfers

Systematization of the Knowledge of Relevant Signals in Evaluating the Surf Zone - Proﬁciency in Positioning in the Surf Zone Lineup and

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were inquired, 2 women included. Actually, those

were the only women in Portugal that had more than

15 years of surf experience cumulated with national

champion titles, for that PL won almost all the

feminine titles (11) and a Guinness World Record

for that. Ages range from 32 to 42, practice time is

above 20 years (except for 2 subjects), 5 are

Physical Education university graduates, 2 authors

of master theses on surfing and 1 PhD in Physics.

All the surf coach masters and all the women meet

the criteria, and several respondents are professional

surf coaches.

5.3 Instrument: Questionnaire

“Relative Valuing, by Surf Masters,

of Signals in the Surf Zone”

The data was retrieved by means of a questionnaire,

with a two level "Rating Scale" (options important/

not important, or no opinion), divided in four parts:

Instructions, Identification, Wave judgement skills,

Wave knowledge skills:

Part 1) Presentation of the project “Proficiency in

positioning in the surf zone and wave catching

choice of relevant signals from the natural context”

and Instructions (1 page);

Part 2) Personal Data (1 page): identification,

profession, academic/ technical formation in sport,

champion titles and years of surf experience, wave

size specialization;

Part 3) Wave Catching motor task, regarding

Wave Judgement skills (4 pages, 75 items, 75

marks). Studies the skill of evaluating the breaking

wave; it’s presented as a classification of indicator

signals from breaking waves’ formation in the surf

zone: points, lines, speeds and strengths from:

1: Wave Profile (1.1 Ramp shape: sub

subcategories 1.1.1 Slope of wave ramp, 1.1.2

Transition curve; 1.2 Lip shape: sub subcategories

1.2.1 Lip thickness, 1.2.2 Lip curtain length, 1.2.3

Lip curve/ tube shape, 1.2.4 Lip strength);

2: Wave Plan (2.1 Wall shape: sub subcategories

2.1.1 Wave wall height, 2.1.2 Wall slope, 2.1.3 Wall

length, 2.1.4 Wall curve, 2.1.5 Angle of swell line

peeling, 2.1.6 Wall curl speed; 2.2 Sections shape:

sub subcategories 2.2.1 Wave sections, 2.2.3 Force

lines, 2.2.4 Force zones in wave sections).

Part 4) Surf Lineup Positioning Motor task,

regarding Wave Knowledge skills (9 pages, 160

items, 595 marks). Studies the skill of sea reading;

it’s presented as a classification of indicator signals

from sea agitation (combined sea ripples and swell

undulation), surf zone bottom configuration and

depth, wave-currents system, wind, tides:

1: Swell > Wave interaction from Groundswell

and Windswell (Sub categories for Surf Conditions:

1.1 Good; 1.2: Medium; 1.3 Easy; 1.4 Difficult; 1.5

Dangerous);

2: Seabed > Wave interaction (Subcategories for

Maritime Geology and Bathymetry on coastal zone:

2.1 Coastline and natural/ artificial obstacles; 2.2

Seabed; 2.3 Surf zone bottom);

3: Currents > Wave interaction (Subcategories

for Water circulation cells, or currents types: 3.1 3.2

3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10);

4: Wind > Wave interaction (Subcategories 4.1

Large scale atmospheric circulation; 4.2 Local

winds);

5: Tide > Wave interaction (Subcategories 5.1

Tide state; 5.2 Spring Tides; 5.3 Neap Tides; 5.4

Onshore wind Setup and Storm Surge conditions);

6: Atmospheric conditions > Visibility signs.

The 160 questions from wave knowledge survey was

the most complex part, since each item had four

options, which meant that each item was actually a

set of four questions: this was done by allowing

independent selection for “Big”/ “Medium”/ “Small

wave” sizes (and for Medium waves also divided in

“Rocky”/ “Sandy” options) – the scale is clearly

included in the Instructions. Some situations do not

have options to mark in all wave sizes options (e.g.,

for the situation Sea Wind – small waves in the

Fetch generating location), therefore the total

number of marks allowed is less than “number of

questions x4”. This enables us to study the lining up

procedures for reaching the primary take-off zone

for these combinations: a) Small/ Medium/ Big wave

heights, and b) Defined Peak/ Multiple peaks.

The total questions number was 235 (75+160),

with 670 choices to mark (75+595); this high

number of indicators inquired reflects the

complexity of analysing/ ordering the very dynamic

(and in a non-linear system) surf zone practice

conditions, and, of course, highlights the expertise

needed to understand the concepts and situations

inquired.

In order to balance the number of questions, it

was designed in digital format (Microsoft Excel),

distributed individually by email, and the item

selection was possible using the keyboard’s arrow

keys and space bar. The respondents would save a

version that was immediately available for data

collection and analysis.

Considering what Bicudo writes about this

survey “these descriptors are too detailed, possibly

waves can be described with fewer parameters”, this

reflects the modelling studies of conditions in the

coastal zone and more particularly on Simulation of

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Waves with software for Artificial surf Reefs

(Cardoso, 2007), of which the author was mentor.

The inquiry had that goal, so that the surfers were

filtered from all the cues presented, as we will see in

the following conclusions.

5.4 Data Analysis

In the global analysis of the grid filling of the

questionnaire we immediately find partial responses

to the hypotheses being studied. From the statistical

analysis of the results we find critical items marked

unanimously as important, and strong categories are

revealed. These main results are presented below.

5.4.1 Hypotheses Verified as True

The propositions that respond to our initial question

are verified as true: H#1 respondents mark the most

signs systematized – they do attend to all elements

of nature in presence; H#2.1 differentiate clearly the

relative importance of the visual signs according to

the wave height scale – surfers value the same signs

differently according to the current surf conditions

(it is observed that they consider more details in

bigger wave conditions or more diffuse windseas);

H#2.2 they need to use more signals at beach breaks

than on stable reef breaks – surfers differentiate the

importance of items according to wave break type.

Therefore our researching Hypotheses about Wave

Knowledge are found true, respectively: H#1. Expert

surfers use indicators of sea conditions regarding

variable specifiers of coastal morphology,

bathymetry, wave-currents system, tides and local

winds for perception of practice conditions; H#2.

Expert surfers value the different indicators

attending to practice situations: H#2.1 according to

the surf height; H#2.2 indicators are valued

according to surf zone bottom type.

The Hypotheses about Wave Judgement are

found true, respectively: H#3. Expert surfers do

divide the wave profile evaluation attending the

slope, ramp shape for the bottom part of the breaker,

and edge thickness/ lip form for the top part; H#4.

Surfers evaluate the form of the wall on the wave

front line for perception of the breaker plan.

5.4.2 Correct Assumptions – Women and

Men are Equally Surf Masters

The assumptions where found correct. The logical

premises underlying this problem (“knowledge and

evaluation of forces in the surf”) were reduced to

minimum so as not to interfere with the validity of

the results, and do not refer to the research method

followed (questionnaire survey) to validate the

classifications systematized. Having found in all

bibliographic research no gender difference

regarding wave knowledge skills, we assumed that

expert surfers could be inquired regardless of

gender. In fact, princesses surfers where much

praised in ancient sport of surfing (Finney &

Houston, 1996) (Pukui, 2003) (Hall, 2004), before

the “civilization” brought role differentiation of

gender in this practice (Gabbard, 2000) there were

always proficient women surfers (Hull, 1976)

(George, 2001) (Brown, 2002) (Heimann, 2004)

(Ford and Brown, 2006) and women have been

training competition surf since it is a profession

(Lowdon, 1988). While outside the scope of the

study, we found no differences in the responses from

the men and women inquired: they are expert

surfers, Portuguese national champions with 15+

years’ experience alike. The results allow us to say

that women and men are equally surf masters.

5.5 Main results - Critical Points for

Reading the Surf

The responses to the different items were processed

in Microsoft Excel, with data first treated by means

of descriptive statistical techniques, analysing

mainly the percentage of occurrences. On closer

examination of the results, we highlighted the

critical points to meet in evaluating the surf (items

considered unanimously as important) and strong

categories (groups of items for each element of the

system) from each factor inquired (Waves, Bottom,

Currents, Wind, Tides). We considered those items

with at least 9 positive responses, from the total of

the 11 experts inquired. Therefore the percentages of

82% or higher, in the analysis by item, are presented

as unequivocally important, and ordered below.

From the various ways to identify visually each

signal (variable of each element), surfers marked

which they use and which despise. These data were

analysed and included in the tables in Appendix.

5.5.1 Swell – Fundamental Signals for

Evaluation of Maritime Agitation

The Total Sea present is the result of the

superposition of windswell ripples and groundswell

undulation (“o Mar total presente é o conjunto da

sobreposição do mar de vento – windswell e

ondulação – groundswell”, in the Portuguese

original). To assess the characteristics of the Swell

and Total Sea, expert surfers consider:

Systematization of the Knowledge of Relevant Signals in Evaluating the Surf Zone - Proﬁciency in Positioning in the Surf Zone Lineup and

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1. Maritime Agitation: totality of superposition of

waves groups comprising ripples and swell

(average height, period, direction, exceptional sets);

2. Swell Height, extension of wash zone;

3. Swell Direction (angle of arrival to coast);

4. Swell Direction Good/ bad (distance of rides,

good wave formation);

5. Swell Period (time between two wave fronts);

6. Characteristics Associated with the Swell

periods of less than 8-10 sec, 10-14 sec and more

than 14 sec (respective heights, length and speed);

7. Condition of the Swell (new, maintaining, old),

e.g.: period of the waves lowering, power

lowering, less frequent series);

8. Grouping Patterns Characteristics (number of

waves per set, size and formation within the same

series [best / biggest waves and how many]).

5.5.2 Swell – Fundamental Signals for

Evaluation of Practice Conditions

To assess the characteristics of the Swell and to

read Practice Conditions, expert surfers consider:

1. Identification of defined peak, consistent,

allowing positioning by lineup of known marks;

2. Identification of defined peak, inconsistent,

necessary to adjust at each set;

3. Identification of characteristics of short period

waves (short wavelength, slow speed, less strength);

4. Timing of sets arrival, duration and lulls

duration;

5. Typical conditions of windswell: situation of

multiple peaks, several wave heights and

directions;

6. Difficult Conditions with Small Waves (local

windswell, disordered and irregular waves, with

undefined peaks), short period waves, different sizes

and directions;

7. Dangerous Conditions with Bigger Waves (sea

and wind creating strong currents, waves breaking

randomly with several patterns present, swell and

ripples from various sizes and directions, sets and

lulls unpredictable, peak and lineup changing).

5.5.3 Seabed – Fundamental Signals for

Evaluation of Type of Surfing Break

To assess the characteristics of the Coastal

Geology and surf zone Batimetry, and also to

define the lineup and references for the lining up

technique, expert surfers consider:

1. Seabed Nature and Type of surf break

(pointbreak, reefbreak, beachbreak, mix);

2. Objects at Sea or shore, relevant to navigating;

3. Reference Marks at the Coastline, for lining up;

4. Danger Coastal Zones, currents/rocks/shorebreaks;

5. Seabed Topography/ Bathymetry/ Slope, when

exposed at low tides, wave sections rising and

breaking (shallows) or crest lowering and speeding

up (deep channel), distance from surf to shore.

5.5.4 Currents – Fundamental Signals for

Localization of Water Circulation Cells

To assess the characteristics of Maritime

Currents types and to the localization of the water

circulation cells, expert surfers consider:

1. Water Volume in current zone: width and

depth;

2. Zones of Surface Turbulence (chop), with

white foam remaining on lulls;

3. Speed of Water moving in the current: surfer’s

displacement, or white-water or floating objects;

4. Strength of the Wash of water moving in the

current (height/ speed of white-water);

5. Location and Speed of Alongshore

Currents: water flowing across the beach in

channels between sandbars/ submarine ridges;

6. Rip Current: zones of convergence of

longitudinal currents, producing a strong wash

flow directing offshore, perpendicular to the

shoreline;

7. Wave-currents System: wave breakers zone

over elevated ridges >> alongshore current >>

ripcurrents in channels between surf;

8. Current Zones, identified by seabed

morphology;

9. Coastaljet Current: Ripcurrent extending

further than the outside: due to piers, deep

channel (bay), rocks, junction alongshore

currents, rivermouth;

10. Increased Water Flow in Channel of

reduced width, next to rocks and artificial

constructions (jetty structures, piers);

11. Ripcurrent across the Lineup;

12. Riptide Current: increased water flow due to

tide getting low;

13. Rivermouth: increased water flow;

14. Shorebreak: wave height, frequency, strength;

15. Wave Surge: wave wash back to sea –

undertow current and backwash waves;

16. Lulls between sets at shorebreak;

17. Current Drift: according relining up.

5.5.5 Coastal Winds – Fundamental Signals

for Evaluation of Sea Surface

To assess the characteristics of Coastal Winds and

valuation of the sea surface and surf formation,

expert surfers consider:

1. Intensity and Strength of Coastal Wind (effects

at sea/ waves/ at land);

2. Effects at Waves from Wind: neutral conditions

(windless), favourable (offshore), adverse (onshore);

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3. Local Variation of Sea Breeze: daytime

variation of wind Direction and intensity;

4. Forecast of Typical Local Winds for synchro-

nization to the best conditions.

5.5.6 Tides – Fundamental Signs for

Evaluation of Water Depth

To assess the characteristics from Tides and

evaluation of the state of the water depth at the surf

zone, expert surfers consider:

1. Tide Period: daily cycle of low and high tides:

one each 12h e25 min;

2. Tide Direction: getting low or high, and

influence at ocean water depth;

3. Tide State and Effects on Breakers (breaking

spot and steepness, lineup);

4. Tide State better for the Surf Spot;

5. Water Depths, looking at the plan where the

peeling wave passes;

6. Depth Quick Changes when in Half tide phase

(in 2h half of the total water level from tide

moves);

7. Tide Conjunction Effects of Greater Ampli-

tude: difficult, quickly changing conditions;

8. Difficult Conditions for Entering/ leaving the

ocean, due to tide state;

9. Local Influence of Effects for Amplifying Swell

Height: peaks good at low tides, or at other phase;

10.Forecast of Local Tide Typically Good for

synchronization to the best surf spot conditions.

5.5.7 Atmosphere – Fundamental Signs for

Evaluation of Visibility

To assess the characteristics of factors regarding

Visibility, expert surfers consider:

1. Poor Visibility: Low Light (sunrise and sunset);

low contrast (foggy – sky and ocean on same

colours); backlight from sun (after midday, at

Portuguese West coast);

2. Low Visibility (Mist or Fog): increased attention

to other signs of waves arrival and passage – surf

sound, perception of surf direction and height

when swell front line passes, bubbles from ridges,

surfacing sediments, perception of currents

speeds.

6 CONCLUSIONS

In sport systematization, we look for means to

quantify and reduce the complexity by relations

between different systems, creating strategies to

simplify everything that looked cluttered/ complex

(Peixoto and Ferreira, 1994). The most relevant

results retrieved from data analysis information,

complying to the relationship with the objectives and

researched hypotheses, show the fundamental points

for the expert surfer’s knowledge used to assess the

surf conditions, systematized (ordered, classified,

then filtered on its importance) in this study. This

led us to the definition of this “wave knowledge”

skill.

We can now answer our starting question and

say: it is possible to systematize the surfer’s “wave

knowledge” about wave-currents dynamics in the

surf zone, by means of a classification of their usage

of relevant visual signals from the coastal process

when evaluating the surf zone.

Regarding the Wave Knowledge, results show

that very experienced surfers evaluate variable

specifiers of all elements of the “waves-currents

system”, considering of greater importance the

factors related to identifying the location, type and

intensity of maritime currents (except under

conditions of small waves), and the swell

characteristics (mainly the direction and angle of

arrival to coast, height, period). The importance of

the characteristics of each element observed varies

according to the wave height and for wave breaks

types (“multiple peaks”/ “lined-up peaks”, roughly

corresponding to ocean bottom types sedimentary/

stable). They pay attention to the configuration/

depth of oceanic bottom, and coast profile.

As for the Wave Judgement, for evaluating the

quality of the surf, surfers consider the general

characteristics of the coastal wind and temporal

characteristics of the tides. For assessing the strength

of the surf and perception of the take off point of

descent, surfers focus on the characteristics of the

different sections (plan of the swell line peeling

zone, or where the curling wave has its critical zone)

and wave face profiles (analysing the slope and

thickness; the bottom curve and top edge/ lip form).

6.1 “Wave Knowledge” Skill, Critical

Points for Surf Reading

These are the critical points to consider in surf

zone reading and objectivity in risk assessment.

For surf conditions evaluation, the fundamental

signs from the coastal process, concerning the

general characteristics of waves and currents, are:

1. Identification of the Maritime Currents:

localization, directions and intensities of the water

circulation cells in the surf zone (except for small

wave conditions, under 1m); mostly to these types

of coastal currents (other drifts are negligible):

1.1. Ripcurrents (agueiro in Portuguese), zones

Systematization of the Knowledge of Relevant Signals in Evaluating the Surf Zone - Proﬁciency in Positioning in the Surf Zone Lineup and

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113

of concentrated current return:

1.1.1. Alongshore currents in places of

longitudinal currents convergence (correntes

longitudinais/ paralelas à costa, in Portuguese);

1.1.2. Ripcurrents in deep water channel

(agueiros de canais profundos);

1.1.3 Riptides (correntes de maré);

1.2. Wave surge and undertow (correntes de

retorno da onda na rebentação direta na costa).

2. Characteristics of coastal geology:

2.1. Seabed type, forms and obstacles;

2.2. Wave break type (point, reef, beach, mix);

2.3. The interaction wave-bottom.

3. Coastal wind characteristics influencing state of

sea surface and surf formation (direction, intensity).

4. Characteristics of the Tide state.

6.2 “Wave Judgement” Skill Definition,

for Wave Formation Evaluation

These are the critical points to consider in wave

judgement. For wave formation evaluation, the

fundamental signs from the coastal process,

concerning the wave profile (ramp shape and ledge

shape, divided where the wave face bends) and wave

plan (wall shape of the breaking wave), are:

1. Location of the Primary Peak and Wave Form

at that Spot (height, slope, wave wall shape, edge

shape);

2. Swell Line Characteristics;

3. Wave Sections Characteristics;

4. Wave Profile, differentiating the top and lower

part of the wave incline;

4.1. Ramp slope (lower part of the wave incline)

4.2. Ramp shape, “fat” or “concave”

4.3. Edge thickness (top part of the wave incline)

4.4. Thickness and strength of the falling lip

4.5. Length of the falling lip

6.3 Extreme Caution Situations

A word on extreme danger situations that were

described unanimously throughout the investigation

that can suddenly arise: any fast rising swell; storm

surge or fetch passing; an exceptional set of rogue

waves; coastal jet ripcurrents; sudden occurrence of

fast moving currents (over 1m/sec) by conjunction

of: very angled to coastline swell direction/ riptide/

deep channel/ confluence of alongshore/ tide state/

currents; big wave (over 3m) swells; endless sets

(waves breaking continuously without lulls); change

in rivermouth flow (such as rain, tide direction

change, sudden opening of dam). Tragedy is

favoured by actions like facing back to shorebreak,

bathing in no surf zones in a beach with surf, going

in surf-swimming without full awareness or advice.

6.4 Recommendations

“When we intend to innovate we question the way

the situations have been organized. [...] When you

try something new, mistakes are made, risks are run,

but it is a form of evolution, in the perspective of

achieving a solution more suitable or better fit in the

different contexts” (Peixoto, 1997). We hope, above

all, to contribute to the public information essential

to Beach Safety, creating a theory for the training of

rescuers, contributing to the scientific area of Sports

Training, laying the foundation for educating

behaviours that become cultural practices.

Application suggestions are available in the thesis

full text, ranging from bather safety to training.

Figure 2: The motivation: Portuguese flag, bathers, Joana.

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APPENDIX

The auxiliary documents, the Questionnaire and all

data charts are available in Technical University of

Lisbon repository, www.repository.utl.pt, from

Brogueira, J., Peixoto, C. (2011). Sistematização do

conhecimento dos sinais relevantes na avaliação do

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Técnica de Lisboa [UTL], Faculdade de Motricidade

Humana, Lisboa.

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