just returned from diving in Thailand with my A75 . Lucky had no problems with fogging....but maybe that was because I used the power off feature . that is my camera was not "on" for the whole dive....yes it was a nuisance having to wait sometimes for the camera to come on to get a photo but then again I did not photograph anything that was moving that fast . Another diver with a canon left his on the whole time and did suffer from some fogging........maybe its the camera getting hot inside the casing that is causing the fogging....i did also put some anti-fog into the casing as well though so probably a combination of both saved me .