Well, you are in luck, as Nashville is within 600 miles of a beach.
Less then 500 miles to either Destin/Ft Walton Beach, or to Gulfport, or just under 600 to Myrtle Beach, about 550 to Hilton Head on the Atlantic. Maybe closer as the bird flies, most of the North Carolina beaches are 650 to 700 or more driving distance. The northern beach resorts of Florida's Atlantic coast are also beyond 600 miles driving.
My preference is Myrtle Beach, having lived there a couple years in the previous century. I would go to Myrtle Beach State Park, if I could get in, where I can fish off the pier and swim in the ocean. That would be a campground.
If you want a swimming pool, you would be looking at the RV parks. I have no experience from which to choose, for MB.
We live in Jackson. Try Heritage Resort in Orange Beach, Al. right on Perdido Bay...private marina and pier...convenient to everything...absolutely first class a quick look at their website will clearly prove it. Check it out. Great guides are available for inshore trout and redfish trips. 480 miles from Jackson. Nashville shud be about the same.
Check out this web site:
My wife and I first visited in 2007 and fell in love with the place. We just left there after 3 weeks. There are 2 pools and a boat ramp into Skull Creek. One of the best restaurants on Hilton Head is on the resort. There is also a county pier next door. Several fishing captains fish out of the marina here. Both back bay & deep sea fishing available.
This is a place you need to see. Look at site # 68.