Purpose: The purpose of this thesis was to identify who is the casualty, who is the rescuer, where and under what circumstances a drowning incident can occur and to develop a risk assessment model of drowning for lifesaving in swimming and other aquatic and non-aquatic activities. Method: Three studies were undertaken. Study 1: The key words ‘drown’, ‘aquatic emergency’, ‘risk factors’, ‘lifeguard’, ‘water safety’, ‘lifesaving’ and ‘rescue’ were used in a literature search aiming to identify quantitative research studies with variables that might involve in a drowning incident. Study 2: A criterion sampling method obtained videos (n=41) containing drowning incidents that were visually observed. Study 3: A combination of convenience and snowball sampling method obtained 34 semi-structured interviews from water safety professionals and aquatic athletes of different nations. The objective and subjective content of the video was recorded, the interviews were transcribed and both texts were inserted in the software NVIVO for content analysis. Conclusions: (1) When there is human activity in, on, around, near and under an aquatic environment, then, a drowning incident might happen to whomever (due to victim’s or rescuer’s mistake), wherever and under whatever circumstances. (2) The factors that determine the outcome of drowning incidents are, in order of significance, rescuer characteristics (Who 1), casualty characteristics (Who 2), location (Wherever), and general circumstances (Whatever). (3) Rescuer characteristics, and their interaction with other factors (mainly with casualty characteristics), appear to largely determine the outcome of drowning incidents. (4) Risk taking behaviour leads to drowning when casualties are willing to seek pleasure by engaging themselves in aquatic activities with risk that perceive as controllable. (5) The 4W model of drowning is a promising tool in lifesaving and lifeguarding.

The activity of scuba diving is used for studying behaviours of U.S. visitors to a popular tourist destination in Mexico. The impact created by human activity can produce marine debris and therefore affect the marine environment. The subpopulation of 181 divers was tested for their current household practices regarding discarding plastic and food waste, providing quantitative statistics for divers‘ referential behaviour. Prior to partaking in scuba diving, certified, trainee, and ―one-day-experience‖ divers attended informal environmental education sessions. Moreover, 30% of all divers involved in the study participated in a web survey analysing the long-term impacts from scuba diving activity. Adapted from the theory of planned behaviour, post-experience observations were used for a Two-Step cluster analysis, which demonstrated that environmental awareness and attitude toward the behaviour can be important predictors for reducing the amount of plastic and food discards in the household. Being a member of an environmental organization does not affect waste management practices, and scuba diving is not a blueprint for behavioural change; however, it definitely plays an important role in creating an awareness of and observing the impacts on the reef. Thus, this nature-based activity is only characterized as a good vehicle for promoting good environmental practices for discarding plastic and food, motivating people to rethink their attitudes toward their behaviour in the household.