You can git Git Rot (pun intended) at West Marine. I'm not sure about the Smith's
epoxy, but West carries West System
epoxy which is very high quality. From you original post, you don't indicate if there is any rot- only delamination. If so, then you should be able to inject
epoxy into each of the layers. be liberal with the
epoxy and let it seep into all the crevasses. Clamp using a crush boards between the clamps and the plywood to distribute the load. Consider using slow set
epoxy hardener to allow it to seep adequately. When hard and after cleaning up the re-lamination, mix another
epoxy batch and brush on a couple of coats on the entire bilge board (and any others that you have) to seal the wood. This is necessary because there is almost always moisture in the bilge even if you have a very dry boat. Consider using a thickening agent like West System Colloidal Silca for the second & third coats to keep the
epoxy from running off. The first coat should not be thickened because you want it to soak into the wood.
I hope that this helps. I'm sure that there may be other techniques (like vacuum bagging instead of clamping) to repair the board, but this one should work with minimal cost and tools. Good luck.