[bigeasy1]

Ditto all the above replies.
I thought the transom on my Tsunami I/O only had one small bad spot,so i drilled a few inspection holes with a holesaw in the inside skin.
You guessed it,the whole transom was toast for the most part,and the few areas that weren't rotted,were saturated and on their way to becoming peat moss at some point.
I'd agree with John B about pouring in epoxy,maybe you would luck out,and it would work,but the odds IMO would be against it.