I have a tiny bit of input in that I also work at sea, a lot of guys re purpose cheap kitchen knives. Small santokus in a decent sheath are really popular, and are awfully close to a sheepsfoot profile. I like the choice you ultimately made, but one thing to think about in the future is that long fixed blades can be awkward to get out of the sheath at certain angles, so make sure you mount it in a location that allows you to draw it easily. (And with either arm! You're going for this thing if you got entangled in something most likely!) As you're a diver you probably have some idea of how to carry the thing already but I'd say put it vertical on your chest like a cave diver. If you're going to be wearing a PFD you may already have a lash tab there for it. I used to carry a pacific salt and a paring knife made by victorinox. The salt goes in my pocket and the victorinox goes in a locking sheath on my chest. After a recent embarassing incident I think I'll be carrying both but am more likely to use the paring knife... You might be surprised how thick of a line you can cut with a sharp, thin knife. And if it costs less than $20 you can replace the thing when it's dull. Not the sexiest thing in the world which breaks my heart as a knife guy but it's very tried and true.