Immersion Research Neoprene Socks
Here's what other sites are saying:
The Immersion Research Neoprene Sock gives you plenty of wiggle room when your feet are crammed into your playboat. This lightweight neoprene booty works well on itsown, or as an insulating layer in your water shoes. A light rubberized bottom adds a bit of grip when you're scouting the next rapid.