i have had great luck with DAP aquarium sealer for the ducer. it's cheap and works. see
http://www.dap.com/product_details.aspx ... ubcatID=27. the sealer is slow curing which reduces air bubbles. i have used other stuff in the past but this works the best and sticks.
just sand alittle and clean it up.
i have a cuda 242. i have had it 4 years. it is finally giving me some problems with depth. in the past, i called tech support a few times about fine tuning the settings. if you use the factory defaults, it most likely will not show fish.
ALWAYS use fish arches (told by several techs) and manual senstivity (about 85% up to 100. this is where you tweak it to find fish). Additionallly, turn off clutter.
the reason why people complain about the low cost units not finding fish. it's the settings. i will probably get a eagle 300 or 350. 300 and 350 are the same. I only need to switch out finder head. the ducer hardly ever go bad. i did look at lowarnce m68c and hummingbird. i'll probably wait on a high cost one. i want a model that i can store to a memory chip and view on pc. but for now i'll stick with the 300.
one last tip. i use trailer quick connects and store battery in plastic box insdie a coors soft cooler. i just snap connects and ready to go. keeps water away from connections and protects the fuse.l