both are good
Posted by: castoff on Oct-30-12 11:43 AM (EST)
My paddling partner has the 76x without buying the marine chart card and it works fine. I like the compact size of the etrex20, and it has some marine map info and coastal tides installed like the 76x.
I would keep either in a clear dry bag and not fully trust the 7 waterproof rating on saltwater. As for floating I just add a foam float to the lanyard to float my camera and one to float my GPS.
Also there are ways to make custom maps from marine charts and load them to a GPS.