It's most likely either a pinhole developed from impact/s over the years or it was a porosity issue from new and is just now "wearing" and beginning to leak. Those "ribs" are chines and serve as structural reinforcement for the bottom plus aid in helping the hull to hold tighter in a corner versus just sliding over the water if the bottom was completely flat. Warranty is the boat mfgrs responsibility but VIA the dealers input. Some warranties cover shipping others require you the owner to get it to the mfgrs plant (and then pick it up once it's finished). G3 is a Yamaha Marine company so you could be given the red carpet treatment or you could be given the redazz! Never know with the mega-corps but I'd venture to say Yammie would make it right if it's not impact related (and they'd fix it then but would be on your nickel). Your "flakey warranty" statement isn't really fair to G3, you are quoting a dealer, NOT G3 themselves! A call to G3 might surprise you how much they'd want to be involved. (BUT they are going to require either the boat to be sent back to them or for one of their franchise dealers to be looking at it and sending them pics/facts.)
But honestly it sounds like you have the problem identified and should be able to fix it via some sandpaper, possibly "very light" roughing with a file and then that jb marine weld compound. Painting afterwards is really just cosmetic and your desire. For extra assurance, the Marine Tex (or likewise 3M 4200) put in that chine on the INSIDE of the boat is an extra layer of assurance should the JB Weld develop any pinholes in the future. Just make sure EVERYTHING is COMPLETELY dry when making the fix. (4200 works with moisture/below waterline as well) A warranty repair would likely have you without the boat for 1-2 months. (A REALLY good dealer would get you a loaner for that period but sounds like your dealer wont give you anything but directions to the bus station!)
Frustrating for sure but at least it's nothing dangerous/structurally related and should be fairly easy to fix yourself!
HL
Last edited by HatchieLuvr; 06-24-2013 at 09:29 PM.