What should we do with the drunken sailor? Research gaps on alcohol-related drowning

The effects of alcohol on physical performance and driving ability are well-established [1, 2] and in many countries drink-driving has become both socially and legally unacceptable and irresponsible. Research, education and policy emphasises the dangers of drink driving, with campaigns and law enforcement throughout high-income countries intended to reduce alcohol-related deaths on the roads [3]. There is an ongoing challenge to view the consumption of alcohol while in, on and around the water in the same way [4]. Regrettably, the drunken sailor (or swimmer) remains a common scenario, often with a tragic outcome.

Blood alcohol restrictions for boating vary from country to country and are often linked to vessel size. However, evidence suggests that many boaters, regardless of their familiarity with the laws, often consume alcohol before or while operating vessels, with many believing that alcohol enhances their enjoyment of boating activities [5]. Worryingly, surveyed river users reported they felt it was more acceptable to drink and operate a vessel than it is to drink and drive on the road [6]. Part of the problem is that random breath testing, recommended by the World Health Organization (WHO) [7] to be one of the most effective measures against drink driving, is much more difficult to implement in aquatic environments. This is likely because of dynamic environmental conditions and a lack of structured networks (i.e. roads) that enable targeted monitoring opportunities, as such is the case in roadside random breath testing.

This is a concerning issue because alcohol is a leading risk factor not only for aquatic incidents such as boating collisions and capsizing—but also for drowning [5] posing risks not just to those who consume alcohol, but also to those around them. For example, inebriated vessel operators may put their passengers at risk while inebriated caregivers may neglect their supervision duties toward children around water.

The WHO considers drowning to be a major cause of preventable injury-related mortality and morbidity and an under-recognised threat to global public health [8]. More than 820 people die from drowning every day worldwide, the majority occurring in low- and middle-income countries [9]. Because alcohol consumption is a significant factor in many drowning deaths worldwide, WHO recommends public awareness programmes that focus on better communication of the dangers of consuming alcohol around water and of inadequate supervision of children near water [9]. Unfortunately, almost two-thirds of the included countries globally indicated having no (42%) or no substantial (far-reaching: 23%) alcohol-focused drowning prevention or water safety campaigns. Most of the existing campaigns were delivered in the Americas, Europe and Western Pacific; a distribution reflecting the prevalence of drowning research from these regions compared to other global regions [10]. However, many countries in regions including within of the Americas, Europe and Western Pacific call for stronger data systems and program evaluations that promote opportunities for knowledge sharing [11].

Evidence from Australia shows a 16% increase in alcohol-related drowning deaths (7% when adjusting for population growth) over the last decade. Drowning deaths involving alcohol primarily occurred in inland waterways, especially rivers, creeks and streams, with only a minority (<10%) in bathtubs and spa-baths [12]. Leading activities before alcohol-related drowning were swimming (29%) followed by unintentional falls into water (15%) [12].

Despite research confirming the link between alcohol consumption to drowning, we are without a nuanced understanding of the problem. For example, to qualify a drowning death as alcohol-related, a blood alcohol content (BAC) of ≥0.05%, a common threshold for drink-driving, is often used [13]. However, the influence of alcohol on a person is dependent on a multitude of factors (e.g. sex, age, ethnicity, genetics and drinking history), and research has shown alcohol has a detrimental impact on aquatic ability at a BAC lower than 0.05% [14]. Therefore, the omission of cases recording BAC at less than 0.05% likely underestimates alcohol's true contribution to the fatal drowning burden. The determination of drowning deaths as alcohol-related using post-mortem assessments of BAC are also problematic, given the process of decomposition can inflate BAC readings [13, 15]. Another problem is that alcohol-attributed drowning deaths are sometimes grouped with other causes of injury or with other substance use making it difficult to determine the impact specifically on drowning fatalities. Similarly, although alcohol is estimated to be involved in 30% to 70% of global drowning fatalities [16], its role in non-fatal drowning remains unclear. Gaps in non-fatal drowning data collection are a complex and far-reaching issue, a problem created in part by inconsistencies in the level of detail and the methods used to record these incidents. Despite this, Australian research has suggested that for every fatal drowning incident there are likely three non-fatal drowning events [17]. Therefore, while non-fatal drowning records are limited, this ratio suggests the full impact of drowning is vastly underestimated.

Moreover, for several reasons, the causal link between alcohol use and drowning remains unclear. First, the link between alcohol and drowning fatalities is established post-mortem and remains often unrecorded for non-fatal drowning incidents. Second, whereas the effects of alcohol on physical performance and driving ability are well-established [1, 2], the specific effect of alcohol on swimming and floating ability remains unknown. This can only be inferred from evidence showing that alcohol use impairs the central nervous system (and, therefore, coordination and vision), increasing heat loss leading to hypothermia and decreasing cognitive processing that leads to risk underestimation and exposure to risky situations [18]. Third, the impact of factors that influence the risk of fatal and non-fatal drowning after drinking (e.g. swimming ability, sex, age, culture, genetics and drinking history) also remain unknown. As is the interplay between contextual factors such as fatigue (e.g. sleep deprivation, hangovers), air and water temperature and the use of other psychoactive substances (both in terms of recreational and medicinal use) and known risk factors such as sensation-seeking, peer influence and societal drinking norms [19].

The 2024 WHO Global Status Report on Drowning concludes that although 29% of countries report alcohol consumption as a contributing factor to drowning, the evidence is insufficient to fully understand the context of this risk, and, in turn, to develop effective policy and intervention responses [9]. It seems then that there remains much to do—in terms of generating better evidence and designing and implementing better prevention strategies and policies—to reduce the preventable loss of life and injury because of alcohol-related drowning.

As the song in our title would suggest, we need to find ways to sober up the drunken sailor (swimmer, surfer, boater and so on). Better yet, we need to discourage alcohol consumption when in, on and around the water in the first place, which is challenging because it is a socially acceptable activity in many parts of the world.

The link between alcohol and drowning is widely recognised, yet the physical and psychological effects alcohol has on the performance of aquatic activities—and consequently on the drowning risk—and the wider circumstances remains poorly understood. Further research is needed to address this and to explore the underlying factors that drive the community to combine drinking with aquatic activities. In doing so, we can better determine the most effective approaches for preventing alcohol-related aquatic injuries and both fatal and non-fatal drownings.

Emmanuel Kuntsche: Conceptualization (equal); writing—original draft (equal); writing—review and editing (equal). Amy Peden: Conceptualization (equal); writing—original draft (equal); writing—review and editing (equal). Hannah Calverley: Conceptualization (equal); writing—original draft (equal); writing—review and editing (equal). Jasmin Lawes: Conceptualization (equal); writing—original draft (equal); writing—review and editing (equal). Maree Patsouras: Conceptualization (equal); writing—original draft (equal); writing—review and editing (equal). William Koon: Conceptualization (equal); writing—original draft (equal); writing—review and editing (equal). Geoff Dickson: Conceptualization (equal); writing—original draft (equal); writing—review and editing (equal).

None.