Fresh water pipe leaking SOMEWHERE!

I recall a galley down Carver and below the galley deck was the potable pump.
The pump out went thru the next aft bulkhead and turned towards the water heater and split through out the boat.
That first fitting after that bulkhead was leaking.
Thru the years of servicing the pump, that fitting started leaking.
Had to cut thru the deck to get to it.
Installed a 6" deck plate and use a Shark-bite 90° fitting.

Where you hiding in St Aug? We can put down some ale and gripe about it together.
Call in Norse to fix it while we watch...

Have you tried isolating areas one at a time to the extent you have valves or ability to do this? This should help you narrow it down. If you have hoses or pipes going into inaccessible places might be worth installing isolation valves so you can drill down to where the leak is. Pretty easy to add valves and fittings these days with shark bite or similar press on fittings. Even if you can’t find the exact place of the leak you should be able to figure out the hose or pipe that is leaking and run a new one and bypass the leaky section.

Sounds like the pressure is going back through the pump into the tank if you can't find it in the bilge. Pump/ check valve may just n a good cleaning.

The trouble with clear liquid leaks is that no trail is left. The leak could be event related, such as only occurring while the shower is in use. to find the source area of a leak, I have lined bilge areas with toilet paper to create the track of the leak. I have heard of sprinkling a powder of some kind in the approach areas so that a trail is left. Detergent powder may be good, if it's powdery enough. Corn starch might be OK. Avoid substances that don't fully dissolve, are environmentally undesirable, difficult to clean up, set up like concrete, discolor or leave a sheen in the water when pumped overboard.

You might put some dye in the fresh water tank. If you can find some UV sensitive food safe dye, that would work really well with a UV light. I have never used dye to find leaks on a boat but have used it very successfully to find leaks in a sub sea pipeline. You will have to flush the tank well but that seems easier than what you are going through now.

Before dye, tissue paper behind the hulls limber passages may help determine the direction the water is flooding the bilge from.
From there, keep narrowing it down to each bilge frame.

Make sure you shut hot water heater off if shutoff valve is in front of it...

Oh,, Water Heater...
Pressure relief valve,, where does that drain..
I remember an issue, when hot, the valve would leak, when cold,, not.
Drove everybody crazy for a while.