Anyone aware of a waterproof digital camera with at least a 10x zoom?

10X, get real. People think that a zoom lens is magic, it's not.
On a 35mm camera "normal is a 50mm lens, so a 10X zoom would have a 500mm
focal length. Check out a 500mm lens on a camera with interchangable lens,
it's huge, and a lens that zooms from 50mm to 500mm would be even bigger.
Also most zoom lens get "slower" (that is; they gather less light) at
their longer focal length. In an automatic camera that means a slower shutter
speed and a greater chance that the camera will shake and ruin the photo during
exposure.
Finally the greater magnification also magnifys any shake you impart to
the camera. Many ,probably most, people will have trouble holding the camera
with a large zoom still enough to be very useful, that's on dry land, in a
kayak the problem would be even worse.
Better to buy the waterproof camera that's available and learn to take the
kind of photos that it is suitable for taking.

Arthur