I wasn't too worried about mineral spirits vs turpentine, they are not going to interact completely differently in the environment. I wouldn't use any non-polar solvent if it was actually going to fall in the water, if the deck is over water, I'd scratch all I said.
Other than cutting down the trees, non-polar solvent is what you need. Turpentine and wd-40 were suggested, but also mineral spirits (which is cheaper). If you could saturate the material to soften it and then scrape it off. Think about going to a stain that uses a non-polar solvent like mineral...
Which is a lot less than a tdb 14 or a dw 16 published weight. one of the under discussed aspects of a stitch and glue boat is the high strength to weight ratio of the wood that provides the structure of the boat. A lot of times I wished mine was heavier, if the hull wasn’t a horsepower hog...
We have for sure earned some easy digging coming from the rocky, tree-rooty, clayey soil of New England. Interestingly we did find lawn grass roots down to about 5-6 feet.
Final story is that it was the fitting itself. If you look in the photo the hose barb threads into the elbow, but the joint...
Got to the bottom just as the sun hit the hole. The poly pipe is attached with a couple crimp connectors and a “u” bolt. Leak seems to be at the junction of poly and elbow. Going to try to get it fixed temporarily with a hose clamp.