I have been happy with a Boye folding knife that I purchased probably twenty years ago.
The blade is made from cobalt and is non-magnetic and corrosion proof. I especially like its low profile that allows me to carry it in my pocket without excessive bulk.
The current version of this knife has a marlinspike/shackle key addition that my version lacks. The shackle key would be handy.
Holds an edge pretty well, and after some use I can open and close it one handed. I have the pointed version, similar to below, less the marlinspike/shackle key of course.
We also gives thumbs up to the Boye knife. We have two the pointed version and the safety version.