This descriptive study was completed with recreational divers who dive for training and sport purposes. The study sample consisted of 132 divers, voluntarily participating in the study, from diving schools in Ankara. All divers who registered at the diving schools to attend recreational diving activities and the instructors in the schools were included in the study until the sample size reached 132 divers. The sample size was calculated on the basis of power analysis (for sample size calculation, the DAN 2008 report data, in which barotrauma rate was 26%, were used). The hypothesis of this research was established with a maximum 15% error, α = 0.05, β = 0.05, 95% power, and 5% type I error.[11, 15]
The research instrument consisted of a questionnaire developed by the researchers [5, 9, 11, 15] and was filled out in face-to-face interviews. The questionnaire was structured by dive certifications defined as level 1 and level 2 divers, dive leaders, and level 1 and level 2 instructors. In Turkey diving schools are overwhelmingly affiliated with PADI or CMAS which differ from each other in characteristics of diving certifications. Level 1 or supervised divers can dive to a maximum depth of 12 m for PADI and 18 m for CMAS under the direct supervision of a dive leader; level 2-autonomous divers can dive to a maximum depth of 18 m for PADI open water divers, 40 m for PADI advanced open water and rescue diver and for CMAS with other scuba divers of the same level; dive leader conducts any specialized recreational scuba diving activities; level 1 instructor teaches and assesses scuba students up to level 1 on their theoretical knowledge and in confined water; level 2 instructor teaches any level of scuba diver in confined water, and gains progressive experience in teaching and assessing open water surface skills. The questionnaire included the following sections: first, socio-demographic variables such as age, gender, educational and marital status, occupation, income; health-related issues such as smoking, alcohol habits, presence of chronic diseases and drug use, surgical operations; and lastly a question regarding participants' level of dive certification. The data regarding health conditions, which were self-reports of the participants, was obtained using the question of having chronic diseases diagnosed by a physician. The first section was completed by all divers regardless of certification level. After ascertaining the level of dive certification, each participant was assigned the relevant part of the questionnaire. The second section of the questionnaire was developed only for level 1 divers (beginners), the third section was for level 2 divers (advanced divers), and the fourth section was for dive leaders, level 1 and level 2 instructors. Second, third, and fourth sections contained questions regarding the traits of diving education including knowledge, skills and practices at the present certification level, the number of total dives, experience, maximum dive depth reached, and history of diving-related health events. All possible diving-related health problems according to divers' levels including mask, sinus, tooth squeezes, drowning, hypoglycemia, hypothermia, ear, eye, and pulmonary problems, cramps, barotrauma, decompression, embolism, nitrogen narcosis, carbon monoxide, and oxygen poisoning were listed and all problems explained in order to ensure standardization of the concept, and comprehension of the problem in the same way in second, third, and fourth sections such as mask squeeze (ie, eye damage due to sticking mask onto the face under excessive pressure) or hypoglycemia (ie, feelings of faintness, weakness, and tachycardia attributed to low blood glucose). The third section contained additional questions such as diving equipment used during diving. The fourth section included additional queries such as total number of divers educated or assisted.
The data were analyzed using frequency distributions, independent-samples t-test for comparing numeric data, and chi-squared (χ2) analyses for qualitative variables. Statistical significance level was defined as p < 0.05. In the second section of the questionnaire pertaining to practicing undersea skills during basic certification level, 26 items were analyzed by division into two groups as fulfilling more than 19 items out of 26, and fewer than 18 items. In the third section of the questionnaire, 30 items regarding educational practices were classified as implementing more than 20 items and fewer than 19 items.