I was at my 1993 Hunter 33.5 last week while on vacation. The boat has been on the hard for 2 years now. ( I am away in a three year assignment). I go each year to clean and check the boat. This time my bilge had diesel fuel in it. In checking all lines, filters and under all sole plates I could not discover the source of the leak. There was no visible path that the fuel traveled from as the majority of the travel was not accessible or visible. I then checked the fuel tank itself and it was empty. The boat was put away with 21 gallons in it. I checked all connections at the tank and all were attached. My only reasonable thought is that there is a hole developed in the aluminum tank from below. Has anyone experienced this and if so, how does one go about replacing the tank. Thanks in advance for any assistance in correcting this problem. On a side note I was advised to put a hole in the bottom of the bilge as the batteries were removed and the bilge would not work if there was a problem. I did put the hole in the bottom of the bilge and sure am glad I did that.