Scuba diving and the stress response: considerations and recommendations for professional and recreational divers.

Scuba diving is an activity that people engage in both for recreational purposes as well as having professional, commercial, and military applications. Scuba diving has often been considered a high-risk activity but, overall, scuba diving has been shown to be a safe activity when divers participate within their experiential, physical, and psychological limits. However, increased physical and psychological stress can quickly arise during diving activities due to unexpected events and situations and may lead to the onset of panic in an unprepared diver. Dive safety is dependent on the ability of a diver to understand the primary signs of stress and panic and attempt to minimise their potential impacts on the immediate situation. The purpose of this review is to examine the stress response in divers, illustrate the role that panic plays in potential diving accidents and fatalities, and provide recommendations to both help understand and manage stress and panic in the diving community in an effort to further increase the overall safety of scuba diving across all applications.

The Effect of Acute Breath-Holding Exercise in Different Conditions on Cognitive Performance in Free Divers / El efecto del ejercicio agudo de contener la respiración en diferentes condiciones sobre el rendimiento cognitivo en buceadores libres

There is a growing trend towards studying human cognition in aquatic environments. At present, there exists a dearth of scholarly investigations pertaining to the immediate effects on executive functions subsequent to a solitary breath-holding training session within the cohort of professional free divers who engage in highly strenuous activities that test their physiological boundaries. The objective of this study was to investigate the immediate impact of breath-holding exercises conducted in varying environments (water and land) on the executive functions of professional diving athletes. The research comprised a sample of 18 male individuals engaged in competitive free diving. The experimental design encompassed four distinct sessions: i) an initial phase dedicated to familiarising participants with the N-back test; ii) a subsequent phase involving the collection of baseline and control measurements for the N-back test; iii) a session focused on obtaining anthropometric measurements; and iv) a final session dedicated to measuring lung capacity. The cognitive assessments were conducted subsequent to the breath-holding exercise protocol, which occurred subsequent to both the land and water sessions. The results indicated a significant difference in reaction times between breath-holding exercises conducted on land and in water (p =.021). The computation of delta values was employed to ascertain alterations in cognitive test outcomes under distinct conditions (water and land) in comparison to the control condition. The findings revealed a statistically significant decline in cognitive performance in the water condition relative to the land condition (z:-2.025, p= 0.043, r= -0.544). This study claims that the implementation of breath-holding exercise training in surface water conditions among divers could potentially result in adverse effects on executive functions. Moreover, it has been observed that the identical breath-holding exercises, when executed in terrestrial environments, exhibit a moderate enhancement of executive functions. The present study posits that the aforementioned findings will make a valuable contribution to the development of training methodologies for athletes and coaches involved in the discipline of freediving. Additionally, these findings are anticipated to offer valuable insights into the physiological well-being of divers.(AU)

Comparing meditative scuba diving versus multisport activities to improve post-traumatic stress disorder symptoms: a pilot, randomized controlled clinical trial.

Background: Post-Traumatic Stress Disorder (PTSD) is a chronic and disabling disease that currently has no fully effective therapeutic solution. Complementary approaches, such as relaxation, sport, or meditation, could be therapeutic aids for symptom reduction. Scuba diving combines sport and mindfulness training and has been found to have a positive effect on chronic stress and PTSD. Objectives: The first objective of this pilot study is to compare the effectiveness of diving associated with mindfulness exercises (the Bathysmed® protocol) with multisport activity in reducing PTSD symptoms. The secondary objective is to compare the impact of the Bathysmed® protocol on mindfulness functioning in the two groups of subjects suffering from PTSD. Method: This proof-of-concept took the form of a controlled randomized clinical trial. The primary endpoint was the severity of PTSD symptoms, measured by the PCL-5 (PTSD Check List) scale. Half of the group were exposed to the Bathysmed® protocol (the experimental condition), and the other half to a non-specific multisport program. Results: Bathysmed® protocol improved PCL-5 scores more than the multisport program but the result was not significant. The protocol was significantly better than the multisport activity in reducing intrusion symptoms of PTSD after one month. Globally, trait mindfulness scores improved up to one month after the course, but the result was not significant. Three months after the course, there was no difference between the two groups with regard to PCL-5 and Freiburg Mindfulness Inventory scores.. Conclusion: Our study demonstrates the value of the Bathysmed® protocol even though it suffers from a lack of power and could only obtain partial but encouraging results. Mindfulness must be practiced over the long term to achieve stable benefits. This probably explains why no differences persisted three months after the course. Further work is needed to confirm the initial results obtained with this pilot study.

Antecedentes:El trastorno de estrés postraumático (TEPT) es una enfermedad crónica e incapacitante que actualmente no tiene solución terapéutica totalmente eficaz. Enfoques complementarios, como relajación, deporte o meditación podrían ser ayudas terapéuticas para la reducción de síntomas. El buceo combina deporte y entrenamiento mindfulness y se ha encontrado que tiene un efecto positivo sobre el estrés crónico y el trastorno de estrés postraumático.Objetivos:El primer objetivo de este estudio piloto es comparar la efectividad del buceo asociado a ejercicios de mindfulness (el protocolo Bathysmed®) con la actividad multideportiva para reducir los síntomas del TEPT. El objetivo secundario es comparar el impacto del protocolo Bathysmed® sobre el funcionamiento de mindfulness en los dos grupos de sujetos que padecen TEPT.Método:Esta prueba de concepto tomó la forma de un ensayo clínico aleatorizado controlado. El criterio de valoración principall fue la gravedad de los síntomas de TEPT, medida por la escala PCL-5 (Lista de chequeo para TEPT). La mitad del grupo estuvo expuesto al protocolo Bathysmed® (la condición experimental), y la otra mitad a un programa multideportivo no específico.Resultados:El protocolo Bathysmed® mejoró las puntuaciones de PCL-5 más que el programa multideportivo, pero el resultado no fue significativo. El protocolo fue significativamente mejor que la actividad multideportiva para reducir los síntomas de intrusión del TEPT luego de un mes. Globalmente, los puntajes de mindfulness de rasgo mejoraron hasta un mes luego del curso, pero el resultado no fue significativo. Tres meses después del curso, no hubo diferencias entre los dos grupos con respecto a las puntuaciones de PCL-5 y FMI (Freiburg Mindfulness Inventory).Conclusión:Nuestro estudio demuestra el valour del protocolo Bathysmed® a pesar de que sufre una falta de poder y solo pudo obtener resultados parciales pero alentadores. Mindfulness debe practicarse durante un largo plazo para alcanzar beneficios estables. Esto probablemente explica por qué no persistieron diferencias tres meses después del curso. Es necesario seguir trabajando para confirmar los resultados iniciales obtenidos con este estudio piloto.

Understanding a population: A methodology for a population-based coastal safety survey.

Drowning is a global public health problem, but accurately estimating drowning risk remains a challenge. Coastal drowning comprises a significant proportion of the drowning burden in Australia and is influenced by a range of behavioural factors (e.g. risk perception, knowledge, attitudes and behaviours) that are poorly understood. These factors, along with those that impact exposure (e.g. coastal visitation and activity participation) all impact on drowning risk. While excellent mortality and morbidity data exists in Australia, a lack of coastal participation data presents challenges to identifying high-risk groups or activities and prioritising prevention efforts. This methods paper describes the development and evolution of an ongoing, annual, nationally representative online survey as an effective tool used to capture valuable data about the Australian population's relationship with the coast. This paper explores how the survey is structured (12-14 sections spanning multiple topics and themes), the different question types used (including open text, 4-digit responses and categorical questions), the sample size (1400-1600 respondents), sampling strategy (using demographic quota sampling which can then be post-weighted to the population if required) and how topics and themes have changed over time to enhance the quality of data collected (i.e., wording changes to enhance participant comprehension or data usability and changing issue-specific 'feature' topics of interest such as campaign evaluation). How the survey is implemented online is described, both practically through to third-party recruitment processes and ethically to maximise anonymity of respondents and ensure data quality. Interim analyses indicate the impact of considering exposure when calculating fatal drowning rates, especially by activity (e.g., crude boating drowning rate 0.12 per 100,000 population vs 0.95 per 100,000 exposed population [relative risk = 8.01; 95% confidence interval: 4.55-14.10]). This study highlights lessons learned in the process of conducting a nationally representative coastal participation survey as well as the strengths and limitations of adopting this approach. Data collected will provide more detailed information on the skills, behaviours, knowledge and attitudes of coastal activity participants. Analyses of this unique dataset will inform research that will underpin development and evaluation of coastal drowning prevention initiatives prioritising those most at risk. It is hoped that the methods detailed within this study may be useful for other countries to develop similar approaches to understanding their own population.

Anxiety impact on scuba performance and underwater cognitive processing ability.

INTRODUCTION: Anxiety is a substantial consideration in scuba diving and may influence a diver's performance and cognitive activities. This study aimed to simultaneously observe the effect of anxiety trait on actual diving performance and underwater cognitive processing ability. METHODS: Twenty-seven scuba divers completed the STAI-T component of the State-Trait Anxiety Inventory, and were subdivided into two groups on the basis of trait anxiety scores ≥ 39 and < 39. Scuba diving performance was measured in a pool. The completion time of four standardised scuba skills was recorded by a diving instructor. The correct completion rate and response time for a cognitive function assessment (number-Stroop test) were measured both on land ('dry') and underwater at 5 metres' fresh water. RESULTS: Anxiety trait was associated with prolonged mask clearing: mean completion time 7.1 (SD 3.2) s vs. 10.8 (5.4) s in low and high anxiety trait divers respectively (P = 0.04). Low (vs high) anxiety trait divers had reduced response times for the number-Stroop test: 49.8 (3.0) s vs. 53.3 (5.4) s (P = 0.04) dry, and 64.4 (5.0) s vs. 72.5 (5.5) s (P < 0.01) underwater. Performance of other skills was not significantly affected by trait anxiety nor correlated with the number-Stroop test results. CONCLUSIONS: Personal anxiety trait prolongs mask clearing and underwater cognitive processing ability but the latter did not affect execution of other underwater scuba diving skills.

Fear of Killer Whales Drives Extreme Synchrony in Deep Diving Beaked Whales.

Fear of predation can induce profound changes in the behaviour and physiology of prey species even if predator encounters are infrequent. For echolocating toothed whales, the use of sound to forage exposes them to detection by eavesdropping predators, but while some species exploit social defences or produce cryptic acoustic signals, deep-diving beaked whales, well known for mass-strandings induced by navy sonar, seem enigmatically defenceless against their main predator, killer whales. Here we test the hypothesis that the stereotyped group diving and vocal behaviour of beaked whales has benefits for abatement of predation risk and thus could have been driven by fear of predation over evolutionary time. Biologging data from 14 Blainville's and 12 Cuvier's beaked whales show that group members have an extreme synchronicity, overlapping vocal foraging time by 98% despite hunting individually, thereby reducing group temporal availability for acoustic detection by killer whales to <25%. Groups also perform a coordinated silent ascent in an unpredictable direction, covering a mean of 1 km horizontal distance from their last vocal position. This tactic sacrifices 35% of foraging time but reduces by an order of magnitude the risk of interception by killer whales. These predator abatement behaviours have likely served beaked whales over millions of years, but may become maladaptive by playing a role in mass strandings induced by man-made predator-like sonar sounds.

Mental stress may cause high gas consumption and accelerated heart rate in fast-descending divers.

The descent is a critical part of a dive, both physically and mentally. Pulmonary ventilation, expressed as respiratory minute volume (RMV) and heart rate (HR) were recorded during fast and slow descents to 35 meters (m) in open water while breathing compressed air, and during swimming horizontally at moderate velocity at an 11-m depth. Values of both types of descents were compared with reference values recorded at 11 m, the "plateau" phase, halfway through the 35-m dives. It is hypothesized that the "slow-descent" and "plateau-phase" values will be less than 'fast-descent values. Depth, cylinder pressure, water temperature and HR were recorded with a dive computer yielding time-averaged means (mRMV and mHR) for the descent and for plateau. Of the 18 divers included, 16 performed the fast descents and 11 made the slow descents. The fast descents (23 m·min-1 vertically), performed with 0-8 fin kicks, yielded mRMVDescent=28 ambient L (aL)·min-1, which is 82% higher (P⟨0.001) than mRMVPlateau of 15 aL·min-1. Further, mHRDescent was121 beats·min-1 23% higher (P⟨0.001), than mHRPlateau of 100 bpm. Slow descents (2.4 m·min-1 vertically) yielded 17 aL·min-1 with mHR=101 beats·min-1, values only slightly higher than at Plateau. The 11-m dive (swimming horizontally) yielded 24 m·min-1 with 32 fin kicks·min-1, mRMV=35 aL·min-1 and mHR=115 beats·min-1. Fast descents cause a higher RMV and HR that cannot be explained by physiology alone. Presumably mental stress is a main contributor. For dives deeper than 20 m, a descent velocity of 10 m·min-1 is recommended to reduce cardiac stress, in particular for older divers.

The impact of health on professional diver attrition.

INTRODUCTION: Approximately 77% of professional divers leave the industry within five years of entry, for reasons that are uncertain. One possibility is that attrition is due to ill-health. The health of New Zealand occupational divers is surveyed by a comprehensive medical examination every five years and by a health questionnaire in the intervening years. Divers are thereby confirmed 'fit' annually. The aim of this study was to determine if divers quit the industry due to a health problem not identified by this health surveillance system. METHOD: 601 divers who had left the industry within five years of entry medical examination ('quitters') were identified from a computerised database. One hundred and thirty-six who could be contacted were questioned about their principal reason for quitting. Comparison was made between the health data of all those defined as 'quitters' and a group of 436 'stayers' who have remained active in the industry for over 10 years. RESULTS: Health was the principal reason for abandoning a diving career for only 2.9% of quitters. The overwhelming majority (97.1%) quit because of dissatisfaction with aspects of the work, such as remuneration and reliability of employment. Besides gender, the only significant difference between the health data of quitters and stayers was that smoking was four times more prevalent among quitters. CONCLUSIONS: The key determinant of early attrition from the New Zealand professional diver workforce is industry-related rather than health-related. The current New Zealand diver health surveillance system detects the medical problems that cause divers to quit the industry.

Diving, cannabis use, and techniques of neutralisation: exploring how divers rationalise cannabis use.

BACKGROUND: Diving medicine literature often regards the use of cannabis as a potential contra-indicator for fitness to dive. With that said, there has been no empirical research done with cannabis-using divers to examine how they subjectively understand and construct the risks that their cannabis use may have on their diving. This study explored how cannabis-using divers rationalise the pejorative associations of cannabis use through rhetorical techniques of neutralisation (TON) that function to deny the risks that cannabis use may have on their diving. MATERIALS AND METHODS: Ten medically-fit professional divers from South Africa were individually intervie- wed. The interviews focussed on each diver's reported recreational use of cannabis. The interviews were transcribed and analysed through a framework for TON originally formulated by Sykes and Matza (1957). RESULTS: Analysis revealed six primary TON employed to refute the pejorative associations of cannabis use on dive work, namely: 1. Denial of responsibility: which denies a diver's direct culpability for their cannabis use; 2. Denial of injury: which asserts that no (serious) harm results from a diver's cannabis use; 3. Denial of victim: which repudiates the potentially deleterious effects that cannabis use may have on a diver; 4. Condemnation of condemners: which minimises cannabis use in relation to other divers' unsafe diving practices; 5. Appeal to loyalties: which situates cannabis use within interpersonal networks to whom a diver has a "higher" allegiance; 6. Denial of penalty: which justifies cannabis use by virtue of a perceived lack of punitive action by a Diving Medical Examiner. CONCLUSIONS: The findings of this research highlight the TON which potentially inform a diver's cannabis use, particularly in relation to their diving. Identifying such TON carry important implications for the ways in which fitness to dive is assessed.

Diving and attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) is a psychiatric condition that affects attention, concentration, impulse control and awareness. Not only these symptoms, but also the medications used to treat ADHD (psychostimulants) pose a risk to both the diver and his or her buddy. This article presents guidelines for recreational diving in combination with ADHD and psychostimulants. These guidelines are based solely on 'expert' opinion and were adopted at a meeting of the Dutch Association for Diving Medicine in 2017.

Can scuba diving offer therapeutic benefit to military veterans experiencing physical and psychological injuries as a result of combat? A service evaluation of Deptherapy UK.

Purpose: To explore the effectiveness of scuba diving in providing therapeutic and rehabilitative benefit to ex-service personnel who have experienced traumatic physical and/or psychological injuries resulting from combat.Methods: This study took the form of a service evaluation of Deptherapy, a UK-based niche charity offering support to military veterans who have experienced life-changing injuries. Deptherapy provides scuba diving qualifications, consisting of theory and practical diving experience, to participants alongside a Peer Support Buddy scheme that provides continuing support to servicemen involved with the charity. A total of 15 male veterans were invited to take part in the study. The methodology comprised retrospective and current quantitative measures of mental well-being and functional ability, utilising the General Health Questionnaire-28, and subsequent semi-structured interviews with participants, their families and health professionals.Results: Participants reported an improvement in levels of anxiety, depression and social functioning, and a reduction in insomnia, following their involvement in organised scuba diving activities. There was a mean average difference of 14.3 points improvement on the General Health Questionnaire-28 scale variants between prior interaction with Deptherapy and current perceptions following engagement with the programme. The positive perceptions, as indicated from the semi-structured interviews, were more pronounced in those whose injuries were predominantly psychological, rather than physical.Conclusion: Scuba diving can offer significant therapeutic benefits, particularly for ex-military amputees experiencing co-morbid anxiety and/or chronic psychological adjustment disorders, notably in terms of improvements in social dysfunction and symptomology of depression.Implications for Rehabilitation Scuba Diving as a TherapyMilitary combat can result in devastating, chronic physical and/or psychological injury.Current research suggests that a combination of medical and psychological therapy may prove to be the most beneficial for military veterans.Scuba diving has the potential to benefit injured veterans due the requirement of complete focus and the feeling of weightlessness when underwater.This article evaluates whether scuba diving is an effective physical and psychological therapy through GHQ-28 analysis and veteran interviews.Scuba diving benefited injured veterans in terms of chronic pain relief and depression symptoms alleviation.

Personality profiles of divers: integrating results across studies.

BACKGROUND: There are numerous reports on diver personality, spanning across five decades, across national boundaries, and using a range of measures to describe diver profiles. However, the range of reports poses challenges to interpreting new studies, particularly when having to compare findings across generations, measurements, and national/cultural contexts. This paper aimed to review and integrate diver personality descriptions, drawing on the available studies that reported trait theory based data for naval and sport divers. MATERIALS AND METHODS: Available studies on diver personality - associated with trait theory - were tabulated and the specific traits associated with divers described. Their findings were then integrated into a synthesised description of personality traits. RESULTS: The results suggest remarkably stable military diver profiles across generations, measures, and navies, with some unique differences observed due to national-cultural variables. It was of particular interest that different measures of personality appeared to present related constructions of diver profiles. Navy divers share, among others, a propensity for adventurousness, a strong sense of self-agency, and low trait anxiety. Unsurprisingly, personality profiling could not be generalised across military-civilian diving contexts, and the same clear profile differentiation of navy divers was not visible among sport divers. CONCLUSIONS: Contemporary local data - in the context of military diving - could productively be compared to the body of existing reports, at least where similar theoretical models are used.

The panic triangle: onset of panic in scuba divers.

Panic arising from physical or psychological stress is a common issue in reported incidents and accidents in scuba diving. Due to its effect on perception, thinking and diver behavior, the panic reaction is often a significant factor in the generation or escalation of problems, potentially leading to injuries and fatalities. The instinctive behaviors associated with panic are incompatible with the constraints of scuba diving (e.g., flight response to threat, leading to rapid ascent). Although the dangers are well known, the psychological mechanisms of panic and the implications for prevention/risk reduction are not sufficiently highlighted to recreational divers. In applied psychology, there are grounded theoretical models which describe the onset and maintenance of anxiety and panic, and an evidence base for approaches to anxiety management. For example, these models are used within structured psychological approaches for people experiencing anxiety disorders; and panic attacks are resolvable. Based on these models and underlying theory, this article proposes a new, accessible model for panic in divers. The potential uses of the model are to: (1) provide a simple framework for divers to understand the onset of panic; (2) promote the need for adequate training; (3) describe the importance of staying within training standards, qualifications and personal limitations; (4) support diver and dive educator understanding of individual factors in panic reactions (e.g. psychiatric conditions) placing greater emphasis on psychological fitness to dive; and (5) draw attention to approaches to improved regulation of emotion and promote individual responsibility.

Health Care Experiences of Korean Women Divers (Jeju Haenyeos).

Jeju haenyeos who enter the sea without equipment to collect seafood while holding their breath have a unique culture; however, studies of their health are limited. This study, using an ethnographic approach, explores how Jeju haenyeos have managed and maintained their health. Snowball sampling yielded 15 participants between July and October 2016. We collected data through participant observation and in-depth interviews and conducted Spradley's research sequence. The main theme of the health-management approach of these women was "a life of listening to the body and mind, controlling greed, and adjusting work for safe diving." However, Jeju haenyeos used preventive drugs and excessive doses of other drugs and lacked an understanding of the ways diverse drugs potentially interact. These findings suggest that community nurses should be cautious and should attempt to educate these patients.

Lost at sea: the medicine, physiology and psychology of prolonged immersion.

In most countries, immersion represents the second most common cause of accidental death in children and the third in adults. Between 2010 and 2013, 561 deaths worldwide involving recreational divers were recorded by the Divers Alert Network. Consequently, there is no room for complacency when diving. Being lost at sea is a diver's worst nightmare. In 2006, a diver was lost at sea off the coast of New Zealand for 75 hours. It is unprecedented that, after such a long time immersed in temperate (16-17°C) waters, he was found and survived. His case is presented and utilised to illustrate the many physiological and psychological factors involved in prolonged immersion and what might determine survival under such circumstances. We also briefly review options for enhancing diver location at sea and a few issues related to search and rescue operations are discussed.

Personality and behavioural outcomes in diving: current status and recommendations for future research.

This paper provides a brief overview of the shift from studies describing the personality profiles of divers to studies exploring associations between personality variables and diving performance in terms of behavioural outcomes. The personality associations that were investigated include performance during training, panic proneness, diving injuries, susceptibility to inert gas narcosis, and the behaviour of tourist divers. The paper concludes with a number of suggested directions for further research on personality and diving that may provide tangible benefits in terms of both enhanced safety and improved performance underwater.

Diving and antidepressants.

Psychoactive drugs pose a risk to both the diver and his or her buddy. Little is known about the safety of diving with antidepressants. Amongst the potential interactions with the diving environment are: somnolence; convulsions; a bleeding tendency (potentially worsening decompression illness, DCI), alterations to glucose metabolism and psychiatric side effects. Fluoxetine may potentially reduce the inflammatory process associated with DCI. This article presents guidelines for recreational diving in combination with antidepressants. These guidelines were endorsed at a meeting of the Dutch Association for Diving Medicine in 2015 and are solely based on 'expert' opinion.

Smoking cessation program among naval diver trainees in the Republic of Singapore Navy.

BACKGROUND: Since 2016, the Naval Diving Unit (NDU) of the Republic of Singapore Navy (RSN) has instituted a smoking cessation trial program for their trainees, instituting a blanket ban on smoking during training hours in order to promote smoking cessation and create a smoke-free culture among its servicemen. For the rest of RSN personnel, they would attend a more costly, established Health Promotion Board (HPB) smoking cessation program, which employs social support strategies, while they undergo basic training in the Navy Military Experts Institute (NMI). METHODOLOGY: We examined the outcomes and direct costs of the NDU smoking cessation trial program, compared with the HPB smoking cessation program in NMI. The primary outcome was self-reported smoking cessation at the end of six months. PRINCIPAL FINDINGS: The NDU smoking cessation program led to 50% reduction among smokers with no additional direct costs. It is comparable to a 59% reduction of smokers among trainees in the established HPB program, which costs US$1,955 per course in 2017. The results of both programs are not significantly different (χ2 = 0.34, P-value = 0.56). Neither program?s participants raised any nicotine withdrawal issues throughout. CONCLUSION: The results of the NDU smoking cessation program suggests that it is not inferior to the established HPB smoking cessation program. More studies should be done to identify factors leading to smoking cessation success among Naval Diver trainees compared to the established program, particularly since the NDU program was less costly and had no engagement with trained counselors.

Turkish recreational divers: a comparative study of their demographics, diving habits, health and attitudes towards safety.

INTRODUCTION: In Turkey, scuba diving has become more popular and accessible in the past decade and there has been a commensurate rise in the number of certified divers. This new generation of recreational divers has not been described in detail previously. The aim of this study was to profile this group, while investigating any gender differences and making comparisons with the global diving community. METHODS: Turkish dive club members and diving forum/blog readers were invited to complete an online questionnaire investigating their demography, medical issues and diving history and habits. RESULTS: The questionnaire was completed by 303 female and 363 male divers. Significant differences were found between the sexes in terms of demographics, diving experience and attitudes toward safety. Previous or ongoing medical conditions were reported by 100 female divers and 141 males. Only 29% of females and 22% of males had been examined by a physician trained to conduct assessments of fitness to dive. Female divers did not report problems while diving during menstruation or while taking oral contraceptives. There was no significant difference in the occurrence of decompression sickness (DCS) and DCS-like symptoms between the sexes. CONCLUSION: This is the largest study to date conducted on recreational divers in Turkey and so carries some value. It profiles their physical and behavioral attributes as well as differences in diving practices between the sexes in Turkey. Our findings should have implications for medical screening and dive training standards.

Self-reported exercise behaviour and perception of its importance to recreational divers.

BACKGROUND: This study examined self-reported physical activity and perceptions of exercise importance among certified divers in two distinct age groups. MATERIALS AND METHODS: Questionnaires were distributed by hand at dive sites in three states of the United States, half to students from an academic programme in scuba diving at a regional university. The survey included questions about health status, dive history, certification levels, structured exercise activity levels and perceived importance of regular exercise to their health, diving ability, and safety. Also included was the Godin-Shephard Leisure-Time Physical Activity Questionnaire, a validated physical activity classification instrument for use among adults. RESULTS: Non-students were older than the students and had greater diving experience. There was no detectable difference between groups in perceived exercise importance to health (p = 0.69), diving ability (p = 0.75), or diving safety (p = 0.25). Fitting age, sex, occupation and number of dives to a generalised linear model to predict Godin-Shephard scores, number of dives was removed first (p = 0.43), followed by student status (p = 0.33). Remaining predictors of Godin-Shephard exercise scores were age (-0.004 per year, p < 0.0001) and sex (males = + 0.11, 95% CI 0.04-0.17, p = 0.0012). Both groups reported similar structured exercise regularity, overall health and perceived importance of regular exercise for health, diving and safety. CONCLUSIONS: Despite acknowledging the importance of exercise, Godin-Shephard scores for physical activity decrease with age.