Be sure to pick up some Dielectric grease to put on all connections... save 15% now!
http://www.kayakfishingsupplies.com/...-Grease/Detail
I have a Lowrance Eagle Fish Easy II that still works great, I dont think you need to spend a lot of money, but just need to take care of what you have. Be sure to store your FF upon launching, and landing, I dont care if it is La Jolla 1ft surf... I bought a small dry back, I just keep in my hatch...
I currently upgraded to the Garmin 178C GPS/FF internal antannae, and love it. I had some issues, but Garmin Customer Service was quick to send me replacement parts, etc. and this probably was due to my neglect and corrosion of saltwater.
I got mine off one of those GPS Discount sites, but if I had to do it over again, I might just go to West Marine and get their 3 year warranty. However, on a lower end unit, I probably would just be careful, and not get the WM warranty... Then again, I am coming up on 3 years, with relatively no problems... Moral of story, just take care of your sh*T!
chris