Model Forum / Radio Controlled / Water Models / February 2006

I saw this on the back cover of Nuts and Volts magazine
and looked up the web site.
http://www.parallax.com/detail.asp?product_id=29144
It's primary intent is as a robot motor controller interfaced to

I'm building a simple small sub and was hoping to use an off the shelf
motor, but of course I'll need to waterproof it.  Any ideas, or a FAQ that
I can reference that will get me on the right track?
TIA