Well I don't know about on a boat but many years ago I was the copilot on a flight with a Flight Engineer under training. The trainer said to his trainee " listen lad there's only two things on this plane that can kill you." Then pointing ahead said " one of them sits there and the other one there! "
I'd go with the owner - most other serious dangers are outside the boat. And those, ships, rocks, bad weather etc will mostly all be avoided by a decent skipper.
Or the open fore hatch on the adjacent boat when crossing in the approved manner when moored alongside. Back in the 1970s the skipper managed to fall down one in the dark and wrenched his shoulder badly. The Greek doctor we visited checked all the angles at which the shoulder hurt!