Water Tank Leak

[Northernguy59]

Happy Spring everyone !

Last fall my water tank developed a pretty big leak and the tank drains to only a few inches remaining at the bottom. I can hear it drain but cant see the leak. I have access to the top and rear of the tank, but its not great. I figured if I install an air stem in one of the access/inspection hatches that screw on and off, I could put some food dye in the water and pump up the tank at very low pressure using a small bicycle hand pump. I also bought an inspection camera that I will try when I get to my boat next month. The tank has two baffles and three sections with one fill inlet and one outlet at the rear of the tank.

It would be a major project to remove the tank and it would be my last resort. If I can't find and repair the leak I thought about ordering some bladders for it as I do have the original tank blueprints.

Any thoughts and input would be much appreciated and thanks in advance.

Nothernguy59