We just bought an Altec Lansing "Boomjacket": BoomJacket | Altec Lansing
Waterproof, floating, shockproof, sand proof, you name it. Forty hours run time on a four hour charge. It's a speakerphone, it'll charge your cell phone, it pairs automatically in seconds .
It's brand new, so I can't speak for its long term ruggedness or reliability. Good sound though; not quite as pristine as the Bose on display next to it, but louder. And the speakerphone has excellent clarity. We love it so far.
Interestingly, it's two-sided. The bass comes out of the back, treble and midrange come out of the front.