I have a Leatherman. Too big & heavy & slow to open to be a "sailing knife" but it gets packed in the bag for trips as a handy tool--not knife.
Have a tiny Swiss Army, that's always in my pocket including on the boat but also goes in the bag with the wallet & keys, doesn't stay in the pocket while sailing because it can get lost too easily.
The "sailing" knife is a dedicated sharp paring knife, not pointed but with the point rounded down to the cutting edge to make accidental stabbings a bit harder. A good top-name stainless kitchen knife actually, that's about 6?7"? long in a sheath. I keep a fine edge on it and make a point of *not* using it if I can get to anything else, so the edge stays sharp. For me it serves the purpose of being available "Now!" with either hand. If someone is caught in a line and something is about to be damaged, I know that with one hand and one stroke I can cut that line.
Straight edge, because I find a straight edge, kept sharp, is easy to keep sharp and cuts by simply pressing it against a loaded line--no sawing motion needed as with a serrated edge. Cheap, simple, no fuss.