I spent most of the day trying to sort out two problems. The first was why the new two-stage charger wasnt working. I concluded that it was broke! The second was trying to find the source of the water that accumulates up under the foredeck.
For at least 6 months we have been getting water into a space under the front deck. This space is accessed by removing the front step. In there is the domestic water pump and the bow thruster tube and bowthruster motor. The access is difficult and the space is cramped. I have had to bale it out regularly, often removing 10-20 litres of water. I came to the conclusion that the water could be from one of three sources.
1) Rainwater making it’s way down from the foredeck.
2) Canal water leaking in from the bow thruster, or bow thruster tube.
3) Drinking water leaking from the plumbing or pump.

I discounted 1) as the water appears even in dry weather, and also in winter when the cratch cover would make large amounts of rain ingress unlikely.
I was rather worried that it might be 2) as there was quite a bit of flakey rust around where the tube is attached to the hull. It was possible that water was seeping slowly in that way. That was potentially very serious as if it got worse then the boat could sink. The problem was that with the difficult access I could see the area where the tube was attached to the hull but I couldnt reach it.
The most likely cause seems to be 3). I had replaced the pump earlier, but this hadn’t changed the situation, so I didnt think it was the pump leaking. I thorougly dried all the various plumbing fittings I could reach and then waited about an hour to see which , if any, became wet. When I went back all the joints were as dry as a bone, but more water had appeared. It must be coming from somewhere else!

The only place where I could only feel, but not see, was behind the bow thruster itself. There wasnt room to get my head and shoulders that far into the hole. It looked as though the new water was coming from that direction so I decided to take out the wooden panel completely rather than work through the access hole.

With this done I could see what appeared to be the problem. The boat had a butyl liner retro-fitted to the drinking water tank. A hole had been cut in the original steel tank and through that poked part of the liner to which a pipe fitting was attached. I could see water oozing out from the space between the liner and the original steel tank. If water was getting into this space, outside the liner, then it could only come from two sources; a hole in the liner or overspill when filling the tank.

I decided that if I could remove all (or most) of the water currently in the space then, when we return to the boat next, if there is just a little new water it’s likely to be an overfill problem, but if there is lots of new water then we probably have a leak.