Were they "breath tested" for being "under the influence"?? If it was a car accident instead of "at sea" being in control of a car whilst "under the influence" is an offence is it not?
In most countries today the same applies to being in control of a boat whilst "under the influence" and carries similar penalties as the loss of life can occure through "impaired awareness". A crime is a crime - no matter how many taxes you pay!