Straight blade with a quick release on the scabbord. If you're under water and need to cut your way free, its panic time and you don't want any impediments in the way of getting the knife in action.

I had a Smith and Wesson knife that clicked into a scabbord and I could mount it upside down. I only had to reach over and pull down to release it. That worked for two seasons and then, unfortunately, something released it, unbeknownst to me, and I lost it. I can't find it anymore on the web site. I also had one from McNutt that was good, but it developed rust.

David
Now A cat sailor