http://diversdiscount.com/resources...ersdiscount.com/shop/product.asp?category=118 has a good product for folks that are not retentive about caring for dive knives.
Ocean Master_TITANIUM KNIFE
* 100% Titanium Blade
* Blunt or Sharp Tip
* Serrated Edge / Line Cutter
* Tank Banging Tip on Handle
* The most advanced quick release locking sheath available
* Auxiliary Locking System (ALS) adds a secondary lock to help prevent knife loss
* Depth Compensating Leg Straps
* BLADE LENGTH: 5´´
* OVERALL LENGTH: 10´´
* BLADE: Blunt or Sharp
* $80
I've handled this knife, and it's folding cousin, and as a diver I gotta say I was very impressed. Of critical importance is a solid grip with a good guard. I prefer the blunt tip in dive knives.
I would add one of the nifty line cutters to his kit as well. For $20 it's of more value than a dive knife.
PS Schuey, Brownie - I do not like the Benchmade for diving for the following reasons. It lacks an "over protective" guard, has no line cutter, is somewhat smallish in the grip (and me with my little boggie hands saying this) for a dive knife and the sheath is lacking.