Mid Coast Maine Moorage
Moorings in and around Rockland/Camden/Belfast are generally very much available. I suspect going forward being more so as folks are receding back a bit From the pandemic.
Transient moorings are always pretty much available in these areas and it doesn't hurt to make reservations a couple of weeks ahead just so when you get there a boat club annual cruise hasn't taken up all the moorings. We have never not been able to stay where we wanted.
A seasonal mooring in these areas are also quite available but I would try to secure one soon. There are many many coastal towns, coves, cities to choose from. The ones you mention are central and a great base for Penobscot Bay. The Boothbay Harbor area is a great base for Casco Bay, Musconguss Bay and within a few hours crusing to Pen Bay.
A favorite place for moorage is Linekin Bay in the Boothbay Harbor area. Linekin Bay Resort offers seasonal moorings, with tender service, use of their amenities and a great shoreside restaurant for what I thought for a reasonable price. It's about an hour driving less to this area than Rockland/ Camden/Belfast and maybe more in the summer.
There are many other places too. Contact me at email@example.com or 207-833-5080 and will give you some tips.
The Maine Coast and Grand Banks boats are classics and go together very well.
36' Grand Banks Classic
Potts Harbor Maine (South Harpswell on Casco Bay)