Originally Posted by fallard
Robes' Oregon 450 is waterproof, but I bet it will sink like a rock if it goes overboard (I've got one.) I was comfortable parking mine in a drink holder, but TakeFive suggested a handlebar clamp that Garmin offers if you are concerned about losing it. If your charter boat has one of these open transoms, you might consider a clamp or tether as cheap insurance.
The $9 handlebar clamp keeps prevents falling overboard by keeping the handheld firmly attached.
When it's out of the holder, I keep it in this clunkly cell phone holder from Home Depot. It just happens to be a perfect fit for the clunky GPS (click the pic for a link to Home Depot's listing):
I attach a couple floats (and my waste tank opener key) to the carabiner, so if it falls overboard it won't sink.
So the only time there's true risk of it sinking is when transferring it from the pouch to the handlebar mount. And that only happens in the slip, where the water's always calm.