I was just down in Port Clyde, yesterday (by road). I've stayed in the harbor but frankly, I give it a pass,...when I'm passing by boat. It's one of the more touristy places along this stretch of the coast, and I don't find it very interesting after being turned off, a few times. Walking around on the public road yesterday, a fella informed us we were on his private property, which was a surprise(you wouldn't have known as it looked like public road).
We anchored off the lee of Hupper Island which forms the harbor of Port Clyde, for an overnight a few years back.
When we asked where we might go ashore, Steve Thomas (in a dinghy) of 'This Old House' former fame, pompously informed us, "Hupper is a private island!!!" He had a house on Hupper. This was particularly annoying because we are (were,...) acquaintance's of his.
No problem, we took the dinghy ashore at the public landing on Port Clyde.
Otherwise, it's a great place to catch the ferry to Monhegan (which is a gem of a place).
There are several great anchorages nearby including Maple Juice Cove (I've yet to anchor there), just up the St. George, to name one.
We particularly like the natural anchorage off Burnt and Little Burnt Island. You can go ashore to the beach and it is snug and picturesque. Many other islands in the area offer options to anchor with far better access to the Gulf if you're coming in or out.
And if you're looking for food, we had dinner at Luke's Lobster in Tenants Harbor last night. Absolutely the best Fish and Chips on the East Coast (I've had it several times, always great). Also the best shoreside lobster shack that we know of. Nice, always friendly people, great setting on the water, unbelievable prices(really). It's the best!
The only problem is they are seasonal. You can get an overnight mooring from a few sources and I'd bet they don't charge for a lunch stop.
Port Clyde lobster shack.