I'm right in there with all of you on replacing the whole thing. However, it's way out of my budget to do it, basically since I don't have the room, the means, or the money to have a boat shop do it. I can feel solid stringer about 8 inches behind the face of the old foam that you see in the photo. And YES, I can dig out more and plan to do so when the nasty weather goes away, along with more of the foam. I already have the new stringer (1x8x12' select pine) waiting to go back in. My main concern was doing the best adhering job to the old stringer with the space I have to work with. Then wrap the entire stringer with roven and glass. The depth is about 8 inches in that space. I already know it'll be tricky, but I'm determined to beef it the best I can.
It's quite dry right now since I have let it air out for about three weeks now. I do plan on letting it dry for about another 6 weeks though. But, at that time, I want to be able to start reconstructing.
I don't believe that I'll have anybody swimming to shore since I will be using the pour-in expanded boat foam to keep her afloat if something happens, but as anal as I am, I feel confident that when I get'er finished, she'll be good and stout for a long while.
Thanks to all for your opinions and advice.