Greg,

I have carried a sheath knife on my life jacket for several seasons for exactly the reasons you gave. My personal favorite is the Gerber River Shorty. I would also consider the Gerber River Guide I if I were starting over.



Both knives have chisel tips for prying, a serrated edge for cutting, and a plastic handle. Both are shorter than the average sheath or dive knife.



http://www.gerberblades.com



-Jamie