Just got back from my first trip with u/w video and would like some help with a pesky problem I had on each dive. I have a blue water filter that is fitted over the lens port and on each dive bubbles would form on both the port and the inside of the filter. On each dive I had to remove the filter and wipe everything clean but it took time and I had a lot of shots ruined because when the bubbles were present it seemed to screw up the auto focus causing it to focus on the bubbles rather than outside. Is there something, maybe anti-fog, that will prevent the formation of bubbles without occluding the lens?