I'm guessing that your enclosure will really help retain heat (less wind). I'm curious, so please post. Also, with an air-temp of mid-70's most of my fam's water comfort zone was 88F (personally I'm completely happy swimming in 79F), without a brisk wind, I'm thinking you could get by at water temp of 85F.DJP1812 said:3. Any calculations on how much the temp would drop overnight without a blanket? I've read I could lose up to 50% of the increase.