In my opinion, a fishfinder would definitely help. I have been looking to buy one since I bought my first kayak in July, but haven't pulled the trigger on one just yet. Between the Helix 5, Lowrance Hook 5, and Garmin Striker I think they all have advantages. If I could justify the cost I would definitely get one with side imaging, which would be extremely beneficial for a kayak. I tend to pick apart areas, since its slower fishing, and if I know what is below the surface it could only help. Just my 2 cents.