Dinghy knives and the like. We were issued the curvedy-blade job shown in post #5 , with orange sheath, std issue, when i started flying training in 1972 odd. Later obtained the straight blade version from a friendly squipper after I donated 5 quid to their coffee fund. It still adorns my retired flying suit.
In training I carried a WW2 commando dagger inside my flying suit and a boy scout clasp knife in my ankle pocket, with other survival stuff. When training was over, I grew up and retired the Fairbairn dagger.