Also make sure all your electronics are wrapped in plastic (reciever and battery - servos should be OK without it). While they won't be completely waterproof, if the plane does nose in, it might prevent them from being completely flooded.

Additional fuel proofing is usually a good idea. Water is going to spray all over the tail section and the wing saddle. If the water soaks in, it will soften and weaken the wood.

Brad