So it is the season where people who are getting married this summer start putting together all of the logistics of their weddings.
So as an Islander who has lived here for several summers can I make a recommendation...
Work out some sort of shuttle system for your guests! Maybe not all of them---but just offer it. Just think
Your 75+ guests and 2 other weddings on the Island means that hundreds more people are coming on the Island JUST for your wedding. If it is a beautiful weekend hundreds of more folks come to the Island. Then bam most of your guests are late, people are missing things and their are frantic to leave the Island (and your reception as well) because they are nervous about making the ferry to leave the Island as well.
Just a thought.
And I promise, Islanders will appreciate it, we love sharing our Island. We don't like long ferry lines any more than anyone else (we just tolerate them better).