[L124C]

Clever idea, but put me down as skeptical! Has anyone used one?
Drainman Bilge Pump
It didn't reassure me when the first review I looked at referred to a using it in a "gondola"!:laugher

 

[L124C]

A friend enjoyed good success using this device on a boat he kept on a mooring.

Good to hear. Seems like that is the intended market, where you would not have shore power to charge batteries and would generally have plenty of wind/wave action.