On my 25.5
the water tank is located in the starboard lazerette. I have an inspection plate on the "floor" of the lazerette that can be opened to clean the tank. A water lines runs from the tank, is split into 2 lines with a "T" fitting, passes through an area below the stern bunk, through two electric pumps and then to the two sinks. Remove the cushions in the stearn sleeping area and move the wood covers to the side. I have two batteries located below the rear dinette seat. I am not certain of the volumes, but I think the fuel tank holds around 10 gallons. Probably about the same for the water tank, but, again, I have not measured and have no specs handy. I don't use the water tank because the water tends to get quite stale over a summer and grows nasty life forms if not used and treated often. I have an inboard diesel engine and the fuel tank is under the forward dinette seat. I have a fuel guage on the tank and a valve to shut off fuel flow on the top of the tank. My 25.5 may or may not be typical. A number of modifications were made by the last owner.
