AMIG (American Modern Insurance Group) is the parent company of United Marine Insurance!!
AMIG / United Marine Ins. will delay, fight and try to deny any and all claims.
Go with Progressive or State Farm as I understand they are the most efficient in handling boat claims.
My boat has been stuck in the shop for over 2 months waiting on them and we still don't have it resolved! The shop says they have had 20 other insurance claims come through their shop that have already been fixed in the same time. Most other insurance company claims are resolved and paid for in two weeks.
My shop says United/AMIG fights every claim that comes through the door. They hire an "independent" inspector that my fiberglass guy won't even allow on his property anymore because they do not believe he is ethical.
Beware of 'Internet based boat insurance" companies. Saving $100 up front is not worth the hassles in the long run. Stick with the majors.