I just purchased a 1978 Morgan OI and I filled the water tank up that is located under the V-Berth and it seemed to work fine. Then I took her out 3 days later and tried to get some water and the tank was dry. I looked in the bilge and there was all the fresh water that I had put in the tank 3 days prior. How is this possible? Is there a drain somewhere in this tank? Clueless.