I'm being asked to shoot video at a water park on a slide for a corporate client (who sells water slides). I'm thinking of going down on my stomach, feet first, with the subject a yard or so behind me (facing forward). Interested in anyone who may have ever done this in the past - any tips?

What are my options for water housings? Looking for something not so heavy that it'll bop me in the face when I hit the splash pool. Also concerned about stabilization. I have an FS-100 right now, I wonder if this might not work:

http://www.amazon.com/Ewa-Marine-EM-VFS-Underwater-Housing/dp/B0085NDZ2O

I have an FS-5 on order, I'm sure there's nothing like this out for the FS5 yet (or for months to come), is there more of a generic underwater housing that screws onto lens threads?

Frankly, I'd just get a GoPro Hero4 and go to town at fairly high resolutions. Maybe a bottle of anti-water drop spray for the lens, although some folks don't find it that effective. You can also give it to the rider and let them shoot selfie style, as well, forwards and backwards. A "Floaty" on the back of the camera might be a good idea, as well.