I had good luck with Gamin replacing my Etrex Legend after it died, send it to them and they might fix or replace it for you. If it says "waterproof" it should be.

They also like to hear a good story about their products, so maybe you can tell them about how you need an altimeter function on it to measure your jumps! <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />