Gopro anti-fogging, put unit in front of Car aircon with case open for 5-10 min, This will put dry air into unit, steal anti- Moisture bags from tablet containers/ Foodstuff bags and put one in unit just b Bfore use
I put the camera in the case in the house with air conditioning on, including the antifog tabs and I leave them in. I have cut the tabs in half to fit more in... Works every time.
Thanks Zac & Geoff! Will try the go pro anti fog tabs. M Holder told me about the air con trick, but I must admit I was slack in doing this as the wind and waves where on.