I once capsized and had my harness hook grab the hiking strap, and pull the boat on top of me. I couldn't get out of my harness. Luckily the mast was taller than the water was deep, so I could keep my head above water. The very next day, I bought a Gerber River Guide knife that I keep in a holster on my harness. I think it's every bit as important as a pfd.

Tim