A knife can serve multiple purposes. It's a cutting tool, and for more than just fishing lines. It's a screwdriver in a pinch. You can pry with it, if needed. And you can use it as an anchor in sand if the current is running.
Personally, in cold water my folding knife is in a dry suit thigh pocket. My travel (hence tropical) BCD has a BFDK zip-tied to one side. Both have come in handy, though thankfully never to cut myself or anybody else free from entanglements.
Personally, in cold water my folding knife is in a dry suit thigh pocket. My travel (hence tropical) BCD has a BFDK zip-tied to one side. Both have come in handy, though thankfully never to cut myself or anybody else free from entanglements.