Recently Imaging Resource has published a thorough test of 7 waterproof cameras. Tested cameras: Canon D10, Pentax W60, Olympus Tough 8000, Tough 6000, Stylus 550WP, Fuji Z33WP, Panasonic T1.
Sadly I must agree with IR's conclusion on my own wp-camera (the Olympus Tough 6000):
"...big complaint is its sluggish performance. Shutter lag and shot to shot times were very slow, making it poorly suited for any kind of action shooting. Given that a camera as rugged as the Olympus 6000 invites use in all sorts of active settings, we find it hard to recommend for the active life it seems designed for."
In figures: start up time is measured by IR 4.2 seconds, Autofocus lag time is 1.24 seconds. This makes it very difficult to capture any moving subject with this camera. For action pics on the water I still prefer my old Sony-camera.