It's worth a try to hale the harbormaster on the VHF, but many places don't have someone at a radio on ship or shore. Tenants Harbor for instance, pick up a green mooring marked Cod End and go ashore. It's a restaurant onshore and someone will eventually find you(or not) at the mooring to collect a small fee or you can find them.

With your CD 22, I'd go deep into Tenants Harbor and anchor. It shoals quickly and while they may post it against anchoring, no one is going to enforce that in shallow water.

Rockland is one of the few harbors(Camden as well in this area) you'll likely raise someone haling the Harbor Master on VHF. These days, people are getting phone numbers for the harbor masters and getting them faster that way. Or with a guide you can hale the few marinas in Rockland on VHF or cell phone and get instructions.
There's plenty of space to anchor inside Rockland Harbor as well, and again, your CD 22 will double the size of the anchorage.

Stonington doesn't have any mooring options right in the harbor but you can tie up at the town dock for a few hours. It's a crusty place but well worth running the working harbor gauntlet to get ashore. You can anchor your CD just across the Deer Isle Thoroughfare in many places.

I think to feel secure in looking for a safe landing, have a good and easily deployed anchor and rode. That's the fastest way to take a time out if things start closing in on you close to shore.

That's a nice boat to be sailing in Maine waters. Under sail, if your outboard lifts(I think it does on the CD22), you can forget lobster pots, you'll slither over every one just like a seal with the underbody on that boat. Good luck.