At first look, I could not see anything at the hoses through the access at the back, and the leak started after a down hill grade so it appears it may be at the front of the tank. Are there any hoses or access points at the front of the tanks?

Follow your fuel fill hoses from the top of the gunwale down, they enter the tanks somewhere. You will have to do some 'looking around corners' with a flashlight and perhaps a borescope if you have access to one (there are some cheap ones out for smart phones now). An iPhone with the headset connected can take pictures where you can't see. (The headset volume bottons trigger the camera.)

Be careful with electrical equipment around fumes ! And I would not do this inside a shop.

Get someone to help. open the hatch and drive the same down the same hill

It did sit for a couple of years in Canada, so I am going to stay positive and say a mouse chewed a hose for now. My gel coat guy said he wants me to help him look for the leak, so I'll try not to think about it for the next couple of weeks. I think he just wants me to be there so I can blow up with my boat. LOL!

I had the same issue with my Tiger parked on a hill bow up with full tanks, big leakage... could never figure where it came from, it was ok for a while then over the winter it wound up being a full leak, had Mark at rage redo my tanks.. check out my thread on here and it shows the process...

Drillin, I can't find that thread, I'd be interested in seeing how it was done and the cost so I can prepare myself.

the thread is called tiger upgrades... mark did mine and it was 14-15k, i sourced the lonseal floor myself, he had the tanks made, 135 gallons each and went a little thicker, i also had him repaint my helms and sliding steps

Easiest way to find it is select drillin name then look at his profile. Then select statistics, the "find all threads started by" It will be the first one

Or here to make it easier
https://www.offshoreonly.com/forums/...-upgrades.html

Thanks I found it. I have read parts of that thread before. I did not realize you have done that much to your boat in the past three years. Sorry to hear of the paint problems. After all of that you deserve a good year of boating, and hope it happens for you this year.