This issue deserves a reply.
In my current game, I have twice had to demolish a dock, in order to free the 4-5 ships trapped between the dock and the nearby fishing wharf.
The current ship path-finding does need improving.
Mind you, so do the workers. I have often done a 'where are all my teamsters at X office', only to find one of them on the wrong side of the island to both home, work and all facilities he needs.
I looked at the last ones thoughts, which were along the lines of;
'I need a walk'
'I think I'll go out and stretch my legs'
'Ah, time for some fresh air'
'What a lovely day for a walk'
Substitute the above for all the correct ones, but all his thoughts were along these lines.
After watching this guy for about 4 months, and amazed that he hadn't died of fatigue, let alone starvation, I left him wandering around his tobacco field, that clearly he held in such awe