Hi Beth, glad to have you aboard (bad pun, I know).... I've always had good luck with You're the Captain boat rentals. They're located at Hamilton's Restaurant at Thomas Drive. Spoke with Mark over there to get a price breakdown on their pontoons -

16ft for up to 6 people runs $109/half day or $179/full day.
20ft for up to 9 people are $129/half day or $199/full day.
24ft for up to 12 folks are $159/half day or $219/full day.

True, that's more then the cost of the shuttle - which is $9.50 for adults, $5.50 for kids, or roughly $45 for your family... but, with a pontoon you control when you come and go, where you go, and how long you hang out at the island.

Whenever we have family or friends from out of town visit, the first thing we do is rent a pontoon and head out to Shell Island. Between the freedom of operating your own boat to the excitement of seeing the dolphins up close and personal, it never fails to be memorable.

You can read more about boating with the dolphins here -

http://www.tripsmarter.com/panamacit...imdolphins.htm