patching a leak

My much-beloved WS Tarpon 140 filled with water on my recent Suwannee trip. Whats the best way to find the leak (put it in a pool and look for bubbles or fill it with water and see where it comes out?)? And when I do find it - whats the best way to patch it?

Thanks in advance

first spot to check
Take a look under the very back edge of the keel/stern. If you ever drag the boat on the stern, you can eventually wear a hole in the stern. I’ve seen it happen on friends’ boats a few times. The hole may be so small that you can’t see it amidst the abrasion in that area. Fill the boat with a couple gallons of water, and lean it back towards the stern. See if anything drips out the back of the keel.

One friend fixed his hole by roughing up the area, and laying up a 6" wide fiberglass cap over the back foot of the keel. I thought it was likely to pop right off, but it’s stayed on for a year.

Another way to fix it (and the way I’d probably choose) would be to get a stainless rub strake from a marine store, and drill holes in the keel to mount it there with machine screws and nuts. If you can’t access the area, use some sort of blind anchor/well nuts/etc. Bed the screws and the back of the plate with a bunch of lexel or polysulfate bedding compound.

Find the leak, find a plastic welder.
Although a small leak such as a poke hole can be fixed by cleaning, abrading the inside of the leak (if you can get at it), applying several layers of duct tape, and “welding” the tape with a hot iron.

Some report luck with vinyl mastic. I haven’t used it.

Finally, go to the West Epoxy site and read up on the new G-flex epoxy. They claim that if you clean, abrade, and flame the repair area, you can apply a G-flex and glasscloth patch that will not pop off. I would think that such a patch might last a long time on a non-whitewater boat.

Check around the scuppers first…
depending on how old the boat is check with a dealer for advise. I’ve seen a lot of Tarpons leak around the scuppers.