I am seeing lots of churning in the water
I understand that grass is the biggest nuisance in Mass waters. If you saw water moving I think the prop is attached. You said you saw bottom vegetation in water. I bet prop is covered in vegetation. I had key on prop dissolved on my B28 and the prop came lose just as I got to travel lift for spring haul out. The prop was not turning the water was still.
1972 Bristol 28