It appears there are two options. One is at the airport which is a distance away from port. The other appears to be closer to port. Any advice on which one we should select and transportation to the rentals. Appreciate your help
Actually, there's one outlet right at the cruise port - It's called Great Island Car Rentals. Haven't used it but I'm guessing that it's there to primarily service arriving cruise ship passengers.https://www.greatislandcarrentals.com/
If your intention is to just rent a vehicle for the day and then reboard your cruise ship that afternoon then that's probably your best bet.
Hi from Wisconsin,
Don't be shy of renting from an off brand Irish company. Dan Dooley, or Treaty or lynch...there are quite a few. They offer new cars and at good prices. Hertz and Avis are twice the price of the off brands.