You might want to check this out. It's one of the options that came up when I Googled "waterproof voice recorder" http://www.asenashop.com/ivn/pr-0/9210.html Looks like it may work for you.
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"Far better it is to dare mighty things than to take rank with those poor timid spirits who know neither victory nor defeat." - Theodore Roosevelt

-USMC Corporal Hess Sherrod B:6/6/84 D:4/6/09 I miss you, my brother.