I found the guy that I bought my Kayak from installed the fishfinder within the seat/feet well area and after awhile I endup with enough water in there despite the scuppers that it could get the unit wet. So I'm looking at moving it out of the seat area and plastic welding the hole closed he put in there for the wires.
I'm tempted to pull it out all together and put it on my boat since it's newer than what's on my boat and I'd use it more. Although if I could get a second mount and transducers/gps antenna I'd use it on both my Kayak and boat.
I noticed you have a fish finder on your yak. Do you use it much? Does it work ok on your Kayak?