Water Tank Woes

Small leak became larger and sleuthing lead to the molded fiberglass water tank. The tank is 108" long, 27" wide, located in the aft stateroom under the bed and conforms to the bilge shape. Only access is 16" x 16" that is at the forward end. Upon opening the inspection plate it became clear it has already received attention at some point in the past. Other than the access plate the only way to expose the tank would be to remove the bed, the 225 gallon diesel tank under the bed, and cut open the floor to expose the top of the tank. There are at least 2 baffles in the tank. My research suggests this is not unusual for Californian yachts, flexing and oil canning of 150 gallons of water for 30 years has resulted in weakened seams and joints.

Is there a spray-in potable water tank lining anywhere on the market for this kind of circumstance? Anyone doing it? We're in the PNW and easy access to Seattle, Everett, Bellingham, etc.

Thanks in advance.

As a follow up there used to be an outfit in Seattle (Felix Marine) that lined fuel tanks. Anyone know if they do water tanks?

Here's a followup to my last followup. Felix Marine is out of business as of 2018 and its successor, FuelCare, closed the marine division in 2019. There is an alternative, Precision Fuel Solutions, located in Kent, WA run by Les Ridell (sp?) who can be reached at 206 664 1173. In addition to fuel tanks they can also line water tanks. The key in both circumstances is access. I hope to have Les out to look at my boat and let me know if he can help. I'll update...

Les NEWELL is the owners name, nice guy.

International Marine has 3 products for water coating. I used 975P. It's a commercial product and does a great job, thick coating. I've used on steel, aluminum and fiberglass tanks. It coating should seal pinhole leaks w/o a problem.
https://www.international-marine.com/type/potable-water-tank-coatings

Sent you a PM.