LtDoc

TxAggie,
There's almost always more than one way of doing something. There's several ways of water proofing electronics and batteries,the simplest probably being to simply put everything in a water tight container of some kind (a baloon for the receiver?). What you might do with the battery just depends on what kind of battery you use. A car battery? Use a 'battery box' and be sure to vent the thing outboard. Nicads, or nimh batteries? Got another baloon? Or, while constructing those pontoons, build in water tight compartments? Ductape a cigar box??
- 'Doc

PS - It's sort of early, not enough coffee, my imagination isn't exactly under control yet... ask a 'T'-sipper??