"Mike: The boat is near Belfast (closest big city is Bangor), which is in the southern area."
Lol! You can't be serious.You must not be from Maine
. Belfast is Downeast,which is 2.5-3 hours from where I'm talking about.(That sure is a nice area,though). I am only 10 mins north of the New Hampshire border. Unfortunately I don't know anyone closer to you,but you should have ZERO trouble finding a reputable guy to modify a cover correctly in that area. Downeast Maine is like the boat building capital of the world.
FWIW,I think I would look into the tower Ken posted above .