More important to have safety equipment on you...if the yak floats away with it all your pretty well fuked.
I got a whistle tied to my PFD and I want to get a small signaling mirror and a small waterproof LED flashlight to carry in the PFD. If I go in I'm more worried about them finding me instead of my Yak
Also make sure if you are going to go fishing in a yak....get a fishing Kayak. Trying to reach behind you and fudging with gear, or loading it up with gear, in something that is made for touring can be a recipe for disaster