Harbor is a better-than-average play with good roles and strong scenes.
The two men and the daughter are characters that are pretty much what they seem, and they held no surprises at least for me.
The mother who is the sister of one of the men has a role that requires a some major character decisions by the actress. Is she uneducated or really not that bright? What is her motivation for the visit--is there a deliberate reason or is it serendiptious? This is the kind of role to rehearse all the many ways she could go in order to find what works for you, the actor. In other words, good actors would want to play her.
Alas, I don't think the play is strong enough to warrant many future productions, but boy, what a role for scene study.
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher