Water leak

[five o clock somewhere]

1988 415 Searay aft cabin. I have water in the hot water tank compartment that is located in the galley floor. About 3 litres every 3-4 days. The hot water tank, shower sump and AC pump are all in this compartment.dried the floor out to source the leak. Put down paper towel on floor and monitored every 15min. Coming from the bow end of the water heater so I remove it to replace with new one and when i took screws out of the bow end of water heater that attach it to the floor a bunch of water gushed into the compartment out of those screw holes. It appears that what ever is under that sub floor maybe the cause of the leak? From what I see it is the bottom V of the hull under there. I have pressure tested old tank and have found no leaks. I drilled a 3/4in hole and installed a clear tube that goes into the area under sub floor about 8-12in and attached to shop vac. Got about 16 litres of water out of there. Two days later did the same thing and got about 4 litres out. The hull when launched was in good condition and no water in there til I first took the boat out for her first run after sitting a month at her slip? I did not hit anything. Anyone with info or knowledge of this I would love to hear from you as this is very troubling to me.

 

[Snapon24]

Check water tank. Maybe leaking into that compartment? I just replaced the water tank for the 2nd time on my 88 340EC

 

[five o clock somewhere]

New tank installed with no leaks. My concern is how did the water get in there to begin with? Dried things out and sucked as much water out as I could. Pressure tested old tank and found no leaks. Wondering if when it was winterized they drained the tank in there and with no bilge pump it would have to be shop vacuumed out. If water was left in there for a few days I could see it leaking through floor as the previous installer never silicones screw holes?? I’ll have to keep an eye and make sure water does not return under that floor.