I have been using Calais Marina as a visitor for many years and find that overall it is well run with reasonable facilities for visiting sailors. The nearby chandler USHIP is very helpful and carries a good variety of fixtures and fittings for emergency small repairs to your boat. The restaurants nearby are good with LeDetroit being my current favourite.
Easy shopping in town with good variety of provisions, the little free bus, called Baladin, is very useful and runs from near the marina up to the main town shopping area.