I now have a Lowrance LCX28c and love it. Hi-def grafics pretty accurate GPS and is also radar compatable. I don't know how water proof it is since I put up the rag-top when it starts raining.
On my last boat I used to put a gallon ziplock bag over the unit to keep it dry and I could easily see thru it to make adjustments and read the screen.

Just my 2 bits worth smile
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When things all go to hell with the world, beans and brass will save your a$$....pass the ammo please