Originally Posted by Berkie
I would be surprised if the servo was at the bottom of just an ordinary bucket of water it would still be waterproof. I have done this with so-called waterproof containers but they didn't pass the bucket test and of course if a 415 sinks it could be at an even greater depth.
A good point...except that this is a foam plane. Even if the hull was completely filled with water you could not sink it
Realistically, all you need is for your electronics to be water resistant. As long as the servos are protected from spray, they should work fine. If you have completely submerged it, then you probably have other damage that will make the loss of a $5 servo not really such a big deal.