Last year I went snorkelling off the coast of Western Australia.
I used a Gorillapod with my GoPro; worked really well as a pistol grip when I was chasing whale sharks and cruising the reefs but it really came into its own when I was able to rest it on the tripod and swim off a little way. The fish that hid when I was close all came out to investigate this new thing in their territory and I got some fantastic closeups.
Having said that, make sure that you tie a wrist lanyard to the camera itself as the ball joints in the Gorillapod can sometimes pop out.
