ORIGINAL: polstery
You don't need a waterproof servo, just a standard servo with aeroplate by aerotrend and the servo will work underwater. I use it on all my boat servos.
Is there is a web that have some tips on how to install the servo on the float, so no water get inside the float. I will use ARF plastic floats from Modelfly/Falcon Trading Co. Is the Cessna 177 Cardinal ARF (the ones that is all plastic)
Isaac