I would definitely skip Bar Harbor if there was going to be a cruise ship there that day/night. The place is a zoo in the summer and is MUCH worse if there is a cruise ship there. Take the Island Explorer bus to Bar Harbor if you want to go there for some odd reason. There are lots of places around MDI that are worth a night. Either of the Cranberries is worth a visit. The nicer hiking trails are on Great Cranberry, but the mooring field is quite rolly due to all the traffic. The mooring field is more pleasant over at Little Cranberry and the island is interesting, but the mosquitos are fierce there in the late afternoon. Both of the Cranberies have free town moorings. The sunrise and sunset from Little Cranberry can't be beat.

A bit further afield from Hall Quarry are Long Island (Frenchboro) and Swans Island. Frenchboro has miles of nice hiking trails and the lobster there is great. Burnt Coat Harbor on Swans is always interesting. If you like a more rustic anchorage, then Buckle Harbor on the NW side of Swans is pleasant. There are several very nice anchorages on the west side of MDI that make a pleasant night and there is always Blue Hill (pick up a mooring from the Yacht Club or, if you are feeling adventurous go into the inner harbor and anchor). The islands of Merchant Row are very nice, particularly early in the season before they have many lobster traps. I also like several anchorages on Deer Isle. The passage south of Deer Isla and north of Merchant Row is very pretty as is the Fox Islands thorofare. As other said, Eggemoggin reach is also a very pleasant sail with several nice places to stop (Wooden Boat, Benjamin River, Bucks Harbor).

As others have said it is a long day from Penobscot Bat to Casco Bay. I have done it, but I think we were underway for 10+ hours. The same is true from Portland to the Portsmouth area. Isles of Shoals is definitely worth a stop unless the weather is poor.

Gloucester is interesting, but a bit too commercial for my taste. That said, the Anisquam (sp) canal that cuts through the Gloucester peninusla is a very idylic passage although the bridge on the Glouster end is VERY tight, but I have been through it on a 50 footer.

In the Boston-Cape Cod Bay area Provincetown is an "interesting stop" for the unique culture there and the great beaches