Someone asked about this, and I didn't know, so today as I was leaving Tampa, I noticed that "Inspiration" was in port, and it reminded me that I promised I'd stop over there and check into this. According to the people who should know at the Port of Tampa, there aren't any rental car agencies at, or near the Port of Tampa, and the agencies located at Tampa International Airport won't make arrangements to drop you off at the Port, when you turn in your car there. However,,,they said that they thought Hertz, and perhaps Enterprise Rent-A-Car both have locations just on the opposite side of downtown Tampa, on Kennedy Blvd., and they probably would run you to the port if needed. The best thing to do is call these agencies, and ask them if this is the case.
That's the best I could do gang. At least, I got to see all the lucky people embarking the "Inspiration" today. (Sure was tempting to try and sneak on.)