Recreational Divers Research Articles

Inner ear decompression sickness after a routine dive and recompression chamber drill: A case report

Inner ear decompression sickness (IEDCS) is an uncommon diving-related injury affecting the vestibulocochlear system, with symptoms typically including vertigo, tinnitus and hearing loss, either in isolation or in combination. Classically associated with deep, mixed-gas diving, more recent case series have shown that IEDCS is indeed possible after seemingly innocuous recreational dives, and there has been one previous report of IEDCS following routine hyperbaric chamber operations. The presence of right-to-left shunt (RLS), dehydration and increases in intrathoracic pressure have been identified as risk factors for IEDCS, and previous studies have shown a predominance of vestibular rather than cochlear symptoms, with a preference for lateralization to the right side. Most importantly, rapid identification and initiation of recompression treatment are critical to preventing long-term or permanent inner ear deficits. This case of a U.S. Navy (USN) diver with previously unidentified RLS reemphasizes the potential for IEDCS following uncomplicated diving and recompression chamber operations – only the second reported instance of the latter.

Pulmonary Effects of One Week of Repeated Recreational Closed-Circuit Rebreather Dives in Cold Water.

Background and Objectives: The use of closed-circuit rebreathers (CCRs) in recreational diving is gaining interest. However, data regarding its physiological effects are still scarce. Immersion, cold water, hyperoxia, exercise or the equipment itself could challenge the cardiopulmonary system. The purpose of this study was to examine the impact of CCR diving on lung function and autonomous cardiac activity after a series of CCR dives in cold water. Materials and Methods: Eight CCR divers performed a diving trip (one week) in the Baltic Sea. Spirometry parameters, SpO2, and the lung ultrasonography score (LUS) associated with hydration monitoring by bioelectrical impedance were assessed at the end of the week. Heart rate variability (HRV) was recorded during the dives. Results: No diver declared pulmonary symptoms. The LUS increased after dives combined with a slight non-pathological decrease in SpO2. Spirometry was not altered, and all body water compartments were increased. Global HRV decreased during diving with a predominant increase in sympathetic tone while the parasympathetic tone decreased. All parameters returned to baseline 24 h after the last dive. Conclusions: The lung aeration disorders observed seem to be transient and not associated with functional spirometry alteration. The HRV dynamics highlighted physiological constraints during the dive as well as environmental-stress-related stimulation that may influence pulmonary changes. The impact of these impairments is unknown but should be taken into account, especially when considering long and repetitive CCR dives.

Caisson Disease among Recreational Divers: Review Literature

Introduction: Caisson disease is one of the most common emergencies in divers with very common signs and symptoms that clinicians must be careful to identify based on a complete history and physical examination. The disease also requires immediate and definitive management, usually hyperbaric therapy for a better prognosis.
 Content: This article discussed the types, pathophysiology, and management of caisson disease caused by the release of nitrogen gas bubbles into the blood or tissues during or after a pressure drop in the environment. This is a disease that can be prevented by paying attention to existing risk factors.
 Summary: Caisson disease or decompression sickness is a collection of symptoms that are often encountered in archipelagic countries and can affect anyone diving for seafood or recreational activities. The symptoms are common, but by knowing the pathophysiology, clinicians can identify the disease and immediately perform therapy, thereby preventing complications such as arterial a gas embolism (AGE) so the mortality and morbidity due to caisson disease can be reduced.

The Influence of Sociodemographic Characteristics and the Experience of Recreational Divers on the Preference for Diving Sites

Understanding the preferences of scuba divers is crucial for authorities to establish appropriate management plans and for service providers to offer a wide range of recreation opportunities to promote long-term industrial sustainability. This study categorized diving preferences into two subgroups (physical and biological) to explore the association between diving preferences and divers’ sociodemographic characteristics, as well as diving experiences through multiple regression analysis. Questionnaire surveys were administered, with 398 completed responses successfully collected from diving hotspots in Hong Kong. Results revealed that divers’ sociodemographic status, particularly monthly salary, could affect their physical and biological preferences. Meanwhile, divers’ diving experience was found to be a significant predictor in figuring out their biological preferences. However, no relationship between diving experience and physical preference was identified in this study. These results could inform management authorities in implementing ecological and environmental protection because biological conditions are considered the most attractive motivation for divers to dive in Hong Kong. Similarly, these results may help managers better understand divers’ recreation needs based on different sociodemographic characteristics and diving experiences to create diverse recreation opportunities while enhancing their satisfaction by avoiding the negative impacts associated with identified preference attributes.

Hazard and catch composition of ghost fishing gear revealed by a citizen science clean-up initiative

Ghost fishing, the continued catch of fishes and invertebrates by lost fishing gear, represents an animal welfare issue as well as a waste of both potential food and ecosystem resources. Fishing gear is lost by both commercial and recreational fishers, and management authorities often lack an overview of gear loss and subsequently potential impact on coastal populations. To investigate the hazard and catch composition of lost fishing gear along the Norwegian coast, recreational divers in collaboration with scientists conducted systematic reporting of retrieved lost fishing gear. Through this citizen science project, a total of 12,101 gear items were retrieved and reported, including traps, gillnets and fyke nets. Combining both data on the catch ratio of the gear and its relative quantity, we identified the five most hazardous gear types to be parlor traps, gillnets, fyke nets, wrasse traps and square collapsible traps. The parlour trap was the most hazardous trap, due to high catchability and quantity. The correct classification of gear type could not be confirmed in 2.8 – 6.1% of the pictures taken by divers, depending on reporting format, and divers reported the wrong gear type in 1.4% of the reports. Brown crab (Cancer pagurus) was the species most often found in retrieved gear. Furthermore, the vulnerable species European lobster (Homarus gammarus) and Atlantic cod (Gadus morhua) were also common. These results can inform future clean up-initiatives and management responses to ghost fishing, including preventive measures against gear loss and gear restrictions and customization.

Distribution of the reef manta ray Mobula alfredi and the oceanic manta ray Mobula birostris in the Philippines: a collaborative effort for conservation.

Little is known about manta ray population size, structure and connectivity in the Philippines. In collaboration with dive operators, non-governmental organizations and authorities, sightings of manta rays were collated into a single national database. Using in-water photographs and videos gathered through citizen science and dedicated research efforts, this study compiled sightings between 2004 and 2020, showing 22 separate sites throughout the archipelago with manta rays present. A total of 392 individual reef manta rays (Mobula alfredi) and 107 oceanic manta rays (Mobula birostris) were identified from the collected footage. Four specific sites in the provinces of Masbate and Palawan together hosted 89% of all identified individuals and accounted for 95% of sightings, highlighting these areas are key aggregation sites. This study also reports the movements of M. birostris within the Philippines, based on photo-identification of three individuals moving 150 km between Cebu and Masbate. Despite the growing number of recreational divers in Daanbantayan and San Jacinto, an 80% decline in M. birostris sightings was observed at these sites. To ensure effective future conservation, it is recommended that efforts focus on the identification and protection of manta ray hotspots and migratory corridors, the creation of a sustainable tourism framework and, most important, the implementation of mitigation strategies to reduce fisheries interactions.

Comportamiento de apareamiento del tiburón limón Negaprion brevirostris (Carcharhiniformes: Carcharhinidae), revelado por la ciencia ciudadana en el Océano Atlántico Ecuatorial

Introduction: Knowledge on the copulatory behavior and mating ground requirements of large sharks, including the lemon shark, Negaprion brevirostris, is scarce, hampering conservation efforts. Objective: To describe an area in the Equatorial Atlantic used as a mating ground by N. brevirostris, as well as part of the species pre-copulatory behaviors based on citizen reports. Methods: Between 2004 and 2019, recreational divers, dive guides and rangers from the Marine Protected Area (MPA) in Fernando de Noronha Archipelago (FEN) recorded courtship behaviour, females with mating scars, pregnant females, and adult males. Results: N. brevirostris was recorded mating in shallow waters (0.5-2 m deep) during the austral summer (December to March). A specific location in the MPA, Buraco da Raquel lagoon, was the main aggregation and mating site for adult N. brevirostris in FEN. Conclusions: Citizen science records allowed the identification of shallow waters as key sites for the reproduction of this shark in FEN. Results highlight the potential of citizen science contributions to knowledge of sharks in nature and show MPAs as essential for habitat conservation of sharks with decreasing populations along the Brazilian coast, such as N. brevirostris. We present management recommendations to protect N. brevirostris there and elsewhere.

Involuntary Breathing Movement Pattern Recognition and Classification via Force-Based Sensors

The study presents a novel scheme that recognizes and classifies different sub-phases within the involuntary breathing movement (IBM) phase during breath-holding (BH). We collected force data from eight recreational divers until the conventional breakpoint (CB). They were in supine positions on force plates. We segmented their data into no-movement (NM) phases, i.e., the easy phase (EP) and IBM phase (comprising several events or sub-phases of IBM). Acceleration and jerk were estimated from the data to quantify the IBMs, and phase portraits were developed to select and extract specific features. K means clustering was performed on these features to recognize different sub-phases within the IBM phase. We found five–six optimal clusters separating different sub-phases within the IBM phase. These clusters separating different sub-phases have physiological relevance to internal struggles and were labeled as classes for classification using support vector machine (SVM), naive Bayes (NB), decision tree (DT), and K-nearest neighbor (K-NN). In comparison with no feature selection and extraction, we found that our phase portrait method of feature selection and extraction had low computational costs and high robustness of 96–99% accuracy.

Using biomimicry and bibliometric mapping to guide design and production of artificial coral reefs

Worldwide, artificial reefs are being installed to simultaneously attract recreational divers and protect deteriorating natural reefs. This study uses a bibliometric review of artificial coral reefs to identify five clusters as gate criteria for artificial reef design. These clusters enable the conceptualization and testing of artificial reefs for optimum integration of sociotechnical requirements, biological integrity, and ecological marine health. The five clusters are: (1) applications, solutions, and performance; (2) management, technology, and science; (3) calcification, biomineralization, chemistry, and ocean acidification; (4) coral species survival, mortality, and photosynthesis; and (5) artificial reef development, and coral and fish recruitment. The six biomimicry design stages are: define, biologize, discover, abstract, emulate, and evaluate. The 3D printing and hard corals design attracted a large number of planula larvae and different inhabitant corals, and a high species diversity in the surrounding waters. Practical implications include biomimicry-based means for coral reef restoration and recreational ecosystem services.

A review of ecological impacts from recreational SCUBA diving: Current evidence and future practice

Global demand for SCUBA diving activities in coastal areas continues to grow. Academic research has acknowledged that SCUBA diving can have ecological impacts. To understand the current state of knowledge this study applied the systematic quantitative literature review method (SQLR) to determine what evidence is available on ecological impacts from recreational SCUBA diving. In total 69 research articles about ecological impacts of SCUBA diving were analysed. This paper explored research trends, geographical distribution of research articles, nature of impact and management recommendations for future practice. The research found that SCUBA diving impacted through diver contact with coral reefs caused breakage, fragmentation and led to disease. 10 coral varieties were identified as impacted including some listed as (critically) endangered or vulnerable by the IUCN. Impacts can be minimized using non-regulatory and regulatory management strategies. We present a novel framework that connects diver characteristics with coral reef impacts and discuss how to apply this framework and guide future studies in this area of SCUBA diving research.

Instagram as a data source for sea turtle surveys in shipwrecks in Brazil

AbstractShipwrecks have been accidentally and deliberately deployed worldwide, becoming artificial reefs for tourist attractions and habitats for marine species. Recreational divers often visit wrecks and post images on Instagram – a popular social network for image circulation. Here we evaluated if such images could be used as a data source for surveying sea turtles in shipwrecks and assessing diver–sea turtle interactions. We targeted the coast of Pernambuco in Brazil, which has over 100 shipwrecks. We inspected public videos and photos posted on Instagram from October 2010 to April 2020. We used 20 tags in our search, which led to 2353 images (210 videos; 2143 photos). A total of 220 posts depicted sea turtles (189 photos and 31 videos; 41 sea turtles in videos and 199 in photos) and their enhanced quality‐facilitated species identification. We detected Caretta caretta (loggerhead sea turtle), Chelonia mydas (green sea turtle) and Eretmochelys imbricata (hawksbill sea turtle). Turtles were found in 13 shipwrecks, all with bathymetry up to 30 m. Photos and videos provided the same proportion of images of each turtle species. Nevertheless, from a temporal perspective, this scenario changed. All three species were observed in photo posts in 4 of the 9 full years considered, whereas all three species were only observed in 1 year in the video posts. We registered four types of diver–turtle interactions from videos: ‘abrupt approach, chase, touch and pose’. We classified ‘abrupt approach, chasing and touching’ behaviours as major disturbances as they altered the turtles’ behaviours. We classified ‘pose’ as a minor disturbance as it caused no apparent change in turtle behaviour. Chasing was the most frequently observed interaction. Instagram is a useful complementary tool that can aid in the surveillance of sea turtles in shipwrecks. However, the limitations of this type of data and adequate data filtering criteria must be considered.

Severe carbon monoxide poisonings in scuba divers: Asia-Pacific cases and causation

Aim: Reports of fatal incidents in recreational scuba divers from carbon monoxide (CO) poisoning are rare. This study aimed to identify scuba fatalities in the Asia-Pacific region caused by breathing-gas contamination to better understand the likely sources of contamination and reduce such preventable deaths. Methods: A hand search of Project Stickybeak reports, subsequent Australian fatality series reports, and of published New Zealand diving fatality reports and associated data was conducted, as well as key word searches of the National Coronial Information System for scuba fatalities in Australia and New Zealand. Cases identified were matched with the Australasian Diving Safety Foundation diving fatality database. Available reports were examined. Results: Four scuba deaths resulting from CO poisoning were identified from 645 scuba fatalities, including one report from each of Australia, New Zealand, Singapore, and the Maldives. A near-fatal incident was also identified in Indonesia. Two of the fatal incidents and the near-fatal incident involved internal combustion engine exhaust gases from the compressor system or elsewhere entering the air intake. Two deaths likely resulted from combustion within compressor systems. Conclusions: Scuba fatalities from CO poisoning are uncommon, albeit likely under-reported. Sources of CO include exhaust gases entering the compressor and CO production by pyrolysis or gasification within the compressor or its filter system. Preventive measures include proper installation (including positioning of the air intake relative to combustion exhaust), appropriate maintenance, fitting of pressure-maintaining valves and avoidance of overheating. Formal training of compressor operators, improved diver education, mandatory requirements for installation compliance assessments, safety inspections, and the use of carbon monoxide alarms are recommended.

Cardiovascular risk assessment in divers: Toward safer diving

Similar to aviation, diving is performed in an environment in which acute incapacitation may lead to a fatal outcome. In aeromedicine, a pilot is considered “unfit to fly” when the cardiovascular event risk exceeds one percent per annum, the so-called 1% rule. In diving no formal limits to cardiovascular risk have been established. Cardiovascular risk of divers can be calculated using the modified Canadian Cardiovascular Society (CCS) Risk of Harm formula: risk of harm (RH: cardiovascular fatality rate per year during diving: number × 10-5 divers/year) = time diving (TD: number of dives × 10-4) × sudden cardiac incapacitation (SCI: cardiovascular diver event rate per year (number × 10-5/year). The SCI and thus the RH are strongly dependent on age. Using the CCS criterion for RH, 5 × 10-5 divers/year, and considering an average of 25 dives per year per diver, the calculated maximum acceptable SCI is 2%/year, consistent with current practice for dive medical examinations. If the SCI were to exceed 2%/year, a diver could be considered “unfit to dive,” which could particularly benefit older (≥ 50 years) divers, in whom cardiovascular risk factors are often not properly treated. For the prevention of fatal diving accidents due to atherosclerotic cardiovascular disease, a dive medical examination is of limited value for young (<50 years) divers who have no cardiovascular risk factors. Introducing a cardiovascular risk management system for divers may achieve a reduction in fatal diving accidents that result from cardiovascular disease in older divers engaged in both recreational and professional diving.

Using recreational divers to inform more efficient conservation management within a MPA - A case study from the Cape Peninsula, South Africa

In South Africa, recreational scuba diving is a popular coastal activity, which is largely carried out within Marine Protected Areas (MPAs). MPAs act as the basis for marine conservation in the country, operating as the primary tool for the management of the country's marine resources. Effective management of MPAs depends on the uptake of voluntary guidelines, including Codes of Conduct by recreational users, such as the scuba diving community. With a focus on the MPA of Table Mountain National Park (TMNP), this paper aims to determine the value that Cape divers attach to the marine environment in which they dive, their understanding of the role of the TMNP MPA, and their knowledge and attitudes regarding its management. A semi-structured questionnaire with responses from around 30% of the local diving community showed that while users attached a high value to the MPA in which they dive, they presented a lack of knowledge around the regulations and conditions involved with diving within the MPA. This is associated with poor dissemination of user information and general awareness. In-depth interviews with dive operators and management personnel of the MPA indicated a disconnect between the different levels of management, operators and users. Based on this research, we propose alternative and additional management strategies for recreational scuba diving that would contribute to the success of the TMNP MPA including increased collaboration with the dive community for citizen science activities, improved stakeholder engagement and better access to information on management regulations and expectations.

Post COVID-19 fitness to dive assessment findings in occupational and recreational divers.

It is now known that COVID-19 has long term effects that may not correlate with clinical severity of disease. The known pulmonary and cardiovascular changes as well as thrombotic tendency could predispose to diving accidents. We aimed to investigate COVID-19 related changes that may cause disqualification from diving among divers who recovered from the disease. Occupational and recreational divers who applied for fitness to dive (FTD) assessment after COVID-19 infection were included. Routine FTD assessments were performed. Details of COVID-19 history were evaluated. Lung computed tomography (CT) scans were advised if not previously performed or if there were COVID-19 related changes in previous scans. Divers with pathological findings were restrained from diving and followed prospectively. Forty-three divers were analysed. Thirteen divers were restrained from diving, all due to persistent COVID-19 related changes in lung CT. The prevalence of CT with at least one lung lesion was 68.2% at the time of diagnosis, 73.3% in the first three months after diagnosis and 19.2% later. The most common CT findings were glass ground opacities and fibrotic changes. Demographic characteristics and COVID-19 history of divers deemed 'unfit' were similar to those deemed 'fit'. Divers who recover from COVID-19 should undergo FTD assessments before resuming diving. A chest CT performed at least three months after diagnosis may be suggested.

Aural health awareness and incident prevention in UK scuba divers.

Otological disorders, including Eustachian tube dysfunction (ETD), are commonly observed in divers. Data were gathered to observe the prevalence of ear disorders, and awareness of ear health recommendations for recreational divers in the United Kingdom. An anonymous online survey included: diver/diving demographics, the validated Eustachian Tube Dysfunction Questionnaire 7 (ETDQ-7) (a mean score of ≥ 2.1 indicating the presence of dysfunction), pre-existing ear health conditions, medications, decongestants and knowledge of diving and ear health guidance. A total of 790 divers (64% males) responded (age range 16-80, median 47 years). An ETDQ-7 mean score of ≥ 2.1 was calculated in 315 of 790 respondents (40%), indicating varying degrees of ETD; 56/315 (18%) recorded a pre-existing ear condition. Ear disorders, (external, middle, and inner ear issues) since learning to dive were recorded by 628/790 (79%) of respondents; 291/628 (46%) did not seek medical advice. ETDQ-7 scores of ≥ 2.1 to 6.6 were reported by 293/628 (47%). Six reported inner ear decompression sickness. Decongestants were used by 183/790 (23%). Two hundred and seventy-seven of 790 divers (35%) had aborted a dive with ear problems. Only 214/790 (27%) of respondents were aware of the United Kingdom Diving Medical Committee guidance regarding ear health and diving. Ear problems and ETD since diving were widely reported in this cohort of divers, with not all divers in this study aware of ear health recommendations and advice.

Fatal diving: could it be an immersion pulmonary edema? Case report

Immersion pulmonary edema is a rare, underrecognized, and potentially lethal pathology developing during scuba diving and other immersion-related activities (swimming or apnoea). Physiopathology is complex and not fully understood, but its mechanisms involve an alteration of the alveolo-capillary barrier caused by transcapillary pressure elevation during immersion, leading to an accumulation of fluid and blood in the alveolar space. Diagnosis remains a challenge for clinicians and forensic practionner. The symptoms begin during ascent, with cough, frothy sputum, and hemoptysis. Auscultation reveals signs of pulmonary edema. Pulmonary CT scan, which is the radiological exam of choice, shows ground glass opacities and interlobular thickening, eventually demonstrating a patterned distribution, likely in the anterior segments of both lungs. Apart from the support of vital functions, there is no specific treatment and hyperbaric oxygen therapy is not systematically recommended. We present a case of fatal IPE occurring in a recreational diver who unfortunately died shortly after his last dive. Diagnosis was made after complete forensic investigations including post-mortem-computed tomography, complete forensic autopsy, histological examination, and toxicological analysis.

Changes in Specific Biomarkers Indicate Cardiac Adaptive and Anti-inflammatory Response of Repeated Recreational SCUBA Diving.

ObjectiveRecreational SCUBA (rSCUBA) diving has become a highly popular and widespread sport. Yet, information on molecular events underlying (patho)physiological events that follow exposure to the specific environmental conditions (hyperbaric conditions, coldness, immersion, and elevated breathing pressure), in which rSCUBA diving is performed, remain largely unknown. Our previous study suggested that repeated rSCUBA diving triggers an adaptive response of cardiovascular and immune system. To elucidate further molecular events underlying cardiac and immune system adaptation and to exclude possible adverse effects we measured blood levels of specific cardiac and inflammation markers.MethodsThis longitudinal intervention study included fourteen recreational divers who performed five dives, one per week, on the depth 20–30 m that lasted 30 min, after the non-dive period of 5 months. Blood samples were taken immediately before and after the first, third, and fifth dives. Copeptin, immunoglobulins A, G and M, complement components C3 and C4, and differential blood count parameters, including neutrophil-to-lymphocyte ratio (NLR) were determined using standard laboratory methods. Cell-free DNA was measured by qPCR analysis and N-glycans released from IgG and total plasma proteins (TPP), were analyzed by hydrophilic interaction ultra-performance liquid chromatography.ResultsCopeptin level increased after the first dive but decreased after the third and fifth dive. Increases in immunoglobulins level after every dive and during whole studied period were observed, but no changes in C3, C4, and cfDNA level were detected. NLR increased only after the first dive. IgG and TPP N-glycosylation alterations toward anti-inflammatory status over whole studied period were manifested as an increase in monogalyctosylated and core-fucosylated IgG N-glycans and decrease in agalactosylated TPP N-glycans.ConclusionrSCUBA diving practiced on a regular basis promotes anti-inflammatory status thus contributing cardioprotection and conferring multiple health benefits.

Effects of the COVID-19 pandemic on SCUBA diving experience in marine protected areas.

Faced with the need for isolation of most people to reduce the transmission of COVID-19, a great concern for the well-being of the population has resurfaced. Considering the numerous benefits of outdoor activities to human health and well-being, we assessed whether the quality of the experience of recreational divers in a marine protected area (MPA) was impacted during the pandemic. We applied a semi-structured questionnaire to divers, collected their socioeconomic profile, preferences, motivations, experiences, and compared the results with those obtained in the previous season. We found that the quality of the recreational diver's experience remained high even during one of the world's biggest health crises. This suggests that the combination of contact with a preserved environment and the adaptation of regulations in favor of visitor safety was enough to stimulate positive experiences. Therefore, we highlight the importance of investing in adaptive management so that MPAs continue to promote ecosystem services such as human health and subjective well-being.Management implications•Quality of experience for recreational divers remained high and was unaffected after the first major wave of COVID-19 cases.•Through adaptive tourism management, MPAs can promote positive experiences even in challenging contexts.•High impact of environmental attributes on the quality of divers' experience reinforces that threats to ecosystems are social impacts.•Socially unequal access to benefits generated by MPAs may negatively influence population's support for these areas.•Efforts are needed to strengthen the equity of distribution of positive social impacts in MPAs.•Potential to provide positive experiences for users must be seen beyond economic value, but as an investment in the population's subjective well-being.

Psychophysiological stress response in SCUBA divers: The contribution of negative automatic thoughts and negative emotions

The research questions in this study were to examine the contribution of negative automatic thoughts and negative emotions, measured by two newly-constructed questionnaires, to psychophysiological stress responses among more experienced military and less experienced recreational divers. Further, we examined whether daily variations in cortisol levels could be attributed to the impact of negative thoughts/emotions rather than diving experience. Altogether 15 recreational and 14 military male divers participated in the dive wherein stress responses were measured by anxiety measures (DASS-21 and STAI) and cortisol salivary concentrations. The results of factor analysis and principal component analysis demonstrated acceptable construct validity and internal consistency of both questionanires. Recreational and military divers did not differ significantly in the proportion of negative thoughts and emotions, while recreational divers had significantly higher levels of cortisol release after awakening and immediately before/after diving, indicating their more intense stress responses. A significant interaction between daily variations in cortisol secretion and negative emotions indicated a greater importance of emotions in response to diving stress rather than diving experience. Accordingly, using a multiple regression analysis showed that more pre-diving negative emotions predicted higher levels of pre-diving anxiety and depression as well as more cortisol release. More negative thoughts predicted higher levels of depressive symptoms, while belonging to a group of recreational divers was a significant predictor of higher pre-diving anxiety. This study points to the importance of considering cognitive and emotional experiences, particularly in recreational divers, for the purpose of prevention of negative psychophysiological stress responses prior to diving.