You might also consider the new single use waterproof 35mm cameras.
Although they don't have adjustable focal lengths at about $15 they are very
cost effective for even someone approaching semi-pro - given the risks of
losing an expensive piece of equipment in rugged conditions. The various
water proof sacks do work ok in most semi-rugged environments. Heck, a
couple of clear zip lock bags would also work fine. Quality on a single
use camera is probably comparable to a $500 digital.

Some time ago I went kayakking on the North Sea and I duct-taped such
a single use camera to my paddle with the following results:

http://www.stud.tue.nl/~okawa/albums/duct.html

The results are not too bad, only point was that there was some sort
of delay between pressing the lever and the making of the actual photo I
only discovered later. And of course watching incoming waves while
making a photo, this didn't always go together well .

The camera costed me about $20, don't remember exactly how much
developing the photos cost. Then there's also the scanning of the photos
for the webpage... For regular use a digital camera would probably be
easier and cheaper; I've certainly seen a few nice sets go for a good
price at eBay.

greetings,
Michiel