Among snorkeling deaths specifically …I kind of have this weird thing that I love researching tourist deaths in Hawaii, it’s quite fascinating but I digress lol…
All are older, obese, alcohol involved, not active or unfamiliar with water. Now there are a number of deaths that involve other factors like ocean currents etc that involve younger people, but specific to this the factors are more significant. That said as in mentioned these deaths are extremely rare. They looked into full face masks but couldn’t find a link. I don’t even know if there are enough events to form any kind of hypothesis