Originally Posted by SteveHam
(nothing but hassle free boating this far - touch wood!)
Oh man, you've done it now!!!!
When you remove the garboard plug, let things drain and dry out a little bit. Then check to see if the transom core is exposed and if there has been any water exposure. The transom core should not be soft and punky. That MIGHT be why you're seeing movement. Or else the movement might have broken the seal and allowed water to ingress (chicken or egg scenario).