The higher the water level the more leverage placed on the structure. Leak most likely is higher based on logic of leak relation to height, but could also be due to increased levered separation stress on wall due water level height increasing both stress and pressure exerted on bottom. I would not let it drain on its own unless you are confident the leak will not lead to split seam. But letting it bleed down and stop on its own will tell you one of two things that the leak is the lowered height it stops leaking or if it leaks lower then it originally did not leak, that the structure is being compromised by stress and making new leaks as water height increases, not from pressure but from structueral chages breaking the seal especially if that seal does not stretch a little lite a fabric liner.
Please go back and look at the early pictures of the frame construction. All of the seams, particularly the corners have solid wood behind them. There's no place for it to move to. There's no movement in the structure.
3 inches is 180 gallons give or take a few. That's 1500 lbs. which sounds like a lot, but divide that by 96 and it's only 15.65 lbs. per sq. foot that is being added to the floor. I don't recall the calculation for forward thrust, but I can assure you that the increase between 27" where it isn't leaking and 30" where it is leaking is minimal.
It isn't leaking like a sieve, but only a trickle. I believe that there is a void or thin spot in the coating that I missed or simply didn't apply enough coating to. The tank isn't draining down any notable amount after over 12 hours of leaking. Do the math on it. If it was draining down one inch (60 gallons), that would be 5 gallons per hour over 12 hours. There's not enough water outside where it's leaking to fill a cup.
When it was at 3700 gallons, there might have been a a gallon after leaking about 16 hours.
