Any advice for shooting, and securing an XL-H1 while white water rafting? I'm going to be doing a lot of this soon, and want to make sure my camera doesn't end up getting ruined. Also, if anyone knows of any good water-tight housings that are also easy to use above water, that'd be great too.

Something like this will provide protection from the spray and an unexpected dunk:

http://www.ewa-marine.de/index.php?id=429&L=0

It won't protect from smashes against hard objects.

Assuming you are going to be wearing a lifejacket, I would get some carabiners etc to firmly attach the housing to your jacket (or some quick-release clips).

If you want shock protection then you need to consider something more like a housing designed for scuba. With the XH-A1, that would be a heavy beast to operate above water.