We are from the other side of Maine and have cruised there the last nine summers. Needless to say, we love it.
A very valuable resource is ActiveCaptain.com It is a free, interactive, online cruising guide. And, the two people who head it up are in Castine ME.
If you have specific questions re the coast of ME north of Rockland, send me a PM.
You say: "It will be particularly important to be able to show up late in the day and, if we can't get a mooring ball, have a secure place to drop the hook."
We like to be on the hook or mooring ball by 1600 at the latest - then we get to visit with our "new neighbours".
Hope to see you next summer.
Rik, Linda and Captain Hook
Irwin Citation 34