My servos are fitted at top (inside) of float to avoid any water in the keel. Also, all my floats are fitted with a 1/8" pipe on top of the floats, front and back, extending down to just clear of the bottom inside. After a flying session, I can suck any water out (never had to, yet!) and I attach a pipe to one of the small float pipes from a small compressor, and blow warm LP. air through the floats for a couple of hours to make sure they are dry inside. Before flying, I fit rubber caps to the pipes. Simple, huh?