What does all this have to do with the "best kayak fish finders" subject? I has to do with the ease of install, ease of use and dependability. The best fish finder to me is one that works, first time out and every time out. It is irrelevant what make or model it is, how much it cost to buy if it "DO NOT WORK".
I am in the group that do not buy combo fish finder and GPS / chart plotter, that is my choice and my reasoning is that when it breaks and I have to send it in for repair I am out both the fish finder and GPS. The combo units are great when they work and easier to install than two separate units on the same limited real estate on the kayak.
The fish finders that I use on the kayak are not water proof, I do not expect them to last more than 1 season and there are seasons where I have gone through 3 fish finders due to submerging the kayak (that is a round about way to say "I flipped it"). I wait for fall sales and buy 3 to 5 units of the same fish finder, this way I have spare transducers that can be used on other kayaks I fish from. To me it's cheaper and makes more sense to buy 3 $100.00 fish finders knowing they will last me for at least one season than buying a +$300.00 fish finder that is not water proof and is just as much junk as my cheap fish finder after I flip it.
Transducers, shoot through, dual beam, through the scuppers, attached to the rudder, glued, submerged in water... etc. I have attached mine to the rudder, a lot of people glue them to a flat area inside the hull, attach them with Vaseline and duct tape. Glue a closed cell foam block with a cutout for the transducer and add water. I have attached the transducer to the seat in a Pungo with the puck resting in a bed of silicone. The weight of the paddler guarantees the bond with no air and it's in the area where water collects and that will help prevent air bubbles.
- If you buy an expensive fish finder make sure it's water proof.
- Decide where to mount the fish finder head
- How are you planning on mounting your Transducer
- What is used to power the fish finder (is it going to power anything else like GPS, compass?)
- How do I attach my battery
- If I run cables to the inside of the hull, what will I use to make sure it's water proof?