Buddy of mine makes custom kydex or concealex sheaths for all kinds of folders and fixed blades. River City Sheaths - Mike S. from Ohio.
I own several of his sheaths. Usually it is a Spyderco Rescue lashed to my PFD. You can also clip it to you belt, or hang it off a chain/cord around your neck. I wipe it down w/ Ballistol or a Sentry Marine cloth.
Every day use, I like a small Spyderco Meerkat folder - stubby blade and it is great for cutting up cardboard boxes.
Best edge holding materials are Talonite & Stellite. Knives made from there materials typically start at about $200 for factory fixed blades to over $600+ for a custom folder. Kit Carson from KY is the guy you want to contact for customs. Camillus makes some of the Talonite fixed blades - you can find those online at stores.
Knives were my previous hobby before I went into saltwater fishing. Regular stainless steel will discolor over time.
