Strut....
the shaft comes out of the boat, extends and then goes through the strut that hangs from the bottom of the boat. And aft of that is the prop....about 1.5" away. You can get a replacement from a shaft/prop shop. Mine is bolted on from the inside and bedded on the exterior of the boat. I would have to move a few things, but it can be done...on some boats easier than others. Get a recommendation for a shaft/prop shop and give them a call. Good luck!Greg