Hi,
I don't know if this will help but we just returned from the Polynesian on Friday night and my husband and three boys rented two watermice boats for $30.00 each for one hour. You could also rent them for fortyfive minutes at $27.00 and thirty minutes for I think $25.00. They had so much fun that the two older boys (13 and 10 yr. old) rented them again right after the first time. I was glad they waited to rent them until the day before we left or I think they would have wanted to rent them daily!
Lowcountry mom of three
You may want to inquire if they have the family boat rental package at the GF. They use to have one aat the Poly. I think it was around $125 for the length of your stay. I can't remember if that was per person or for a family.