How can I stop condensation forming in my underwater camera housings?
First, make sure you fasten your underwater camera housing in an air-conditioned room/car or purge the air inside your housing with the air from your diving cylinder. Both these methods will reduce the amount of moisture in the housing. Also try Leak Insure Absorbent Sachets, not Silica Gel, they react faster, and can also absorb water from leaks.
