I carry a folding knife in pocket for a couple reasons.
1. I did a test in 1991 with several sheath knives and a gerber folding knife to see which blade could actually cut someone out of a kayak. The fat blades of the sheath knives where useless while the thin Blade of the gerber could stab in and pull through the kayak like butter. That said only a saw could get through the combing of the kayak.
2. As a kayaker, I have never liked having a knife in my way when paddling. I think knives that stick out pose a hazard with being caught, pulled out of the sheath, and then you have a knife falling who knows where.
3. I have fed the river enough $40 sheath knives. Admittedly, not the newer generation like the copilot.
I am more nervous about being entrapped when I am rowing or teaching swiftwater courses. I keep a folding knife in the knife slot/pocket on the pocket flap of the Green Jacket. It is covered so that the knife can not get caught in ropes but I have a piece of cord that sticks out and I can grab and pull.
Just my opinion and mostly based on personal preference instead of facts.
friend of the fork, knife, and spoon