Most everyone that rebuilds their transom actually moves the low point in their hull forward about 12" and then the bilge water can't drain out anymore through the new drain hole (like mine). Most people don't realize they are creating this problem (I didn't) so maybe this topic can help them before they need it. So, here you go:
If you look at the low spot in a factory hull it is at the transom where the drain hole is (top portion of pic) - As we start to lam in new core and all the layers of the low point moves forward in the hull (lower portion of pic)
I think my low spot is now about a foot in front of the transom - if I would have thought this through earlier I wouldn't have the drain problem (everyone has this problem if they rebuild their transoms "beefy")
So if you glue a 12" length of 1" ID PVC to the hull with it aligned with the hole and cut the core around it and as you lay you lams, include laying it over the PVC, you can eventually grind back the PVC at an angle at the low spot in the hull.
Here is a thread where Hawgleg followed this idea - he says it works great. I always have a 1/2" of water in my bilge now
http://classicaquasport.com/smf/index.php?topic=13148.msg134262#msg134262
