Rent a bike or even sign up for a Segway tour of Sanibel at Billy's Rentals (800-575-8717; www.billysrentals.com). At Tarpon Bay Explorers (239-472-8900 www.tarponbayexplorers.com), sign up for canoe, kayak, or fishing tours of the "Ding" Darling Refuge, a 6,000-acre wetland.
Where to Eat: A funky Sanibel classic, McT's Shrimp House and Tavern gets rave reviews for its conch chowder, oysters and steamed seafood platter, though you'll want to save room the legendary Sanibel Mud Pie – if you can (www.eatmoreshrimp.com; 239-472-3161).
Where to Stay: The Sanibel Inn (866-565-5480; www.sanibelcollection.com) has 600 feet of beach, an L-shaped pool, bird- and butterfly gardens, access to The Dunes Championship Golf Course, free bikes with kid carriers, and suits with sleeping capability for up to six people. On Captiva, South Seas Island Resort offers kids camps, sailing lessons, and tennis courts (doubles from $154, 877-205-1293, www.southseas.com).
9. Texas: Mustang Island, Port Aransas/Fishing
Everything is big in Texas, including the fish. Which is why you may want to check the hurricane patterns and -- if the coast is clear -- head to Mustang Island, just northeast of South Padre Island National Seashore.
The Port Aransas Ferry System provides free transportation service from Port Aransas to Mustang Island seven days a week, twenty-four hours a day. In addition to sand that seems to stretch on forever, the bays, jetties, and deep Gulf waters are home to speckled trout, redfish, black drum, flounder, Spanish mackerel, king mackerel, kingfish, tarpon, sheep head, sailfish, marlin, tuna...the list goes on and on. Captain Ivey's Charters (call 361-749-4302, 800-552-3486 or go to www.fishingportaransas.com/ivey/ ) offers five-hour deep-sea fishing trips starting at $450 for three people.
For world-class kiteboarding, visit nearby Bird Island Basin off Padre Island National Seashore. Take a lesson at Air Padre Kiteboarding (prices range from $200; call 956-299-9463 or go to www.airpadrekiteboarding.com).
Where to Eat: At sundown, head to Buelah's to dine on local blackened redfish and their signature Chocolate Silk pie (361-749-4888).
Where to Stay: The historic Tarpon Inn (doubles, $69-$79; 361.749.5555, www.thetarponinn.com/ ), built in 1886, claims to be the birthplace of sport fishing in Texas. Or rent one of the pastel-colored Latitude 28 cottages (start at $129, 361-739-7292, www.latitude28cottages.com), and time warp back to the fifties era of Texas beach living.
10. Massachusetts: Cape Cod — Wellfleet/Swimming/Biking/Having Fun
Here's a statistic that says it all: 61 percent of Wellfleet is Cape Cod National Seashore Park. About 33 miles north of Hyannis, Wellfleet is also home to the Cape Cod National Seashore Headquarters and the 1,000-acre Massachusetts Audubon Society Wildlife Sanctuary. In addition to swimming, surf fishing, and eating oysters, there's an innovative summer-long children's program that includes dance lessons and yoga on the beach.
For more information, go to: www.wellfleetma.org.
If the kids still have time to play, rent beach cruisers from Rail Trail Bike Shop (508-896-8200, www.railtrailbikeshop.com) and pedal the 26-mile Cape Cod Rail Trail, a ribbon of pavement that runs from Dennis to Wellfleet.
Where to Eat: Satisfy that craving for fresh, buttery lobster and down east clam bakes at Moby Dick's, a seaside restaurant complete with cheesy, seascape murals and the requisite lifesaver on the wall (www.mobydicksrestaurant.com, 508-349-9795).
Where to Stay: Rent one of 19 Surfside Colony Cottages (508-349-3959, www.surfsidevacation.com/), an unpretentious fleet of vacation homes, many of which back right up to the beach. Three-bedrooms start at $1,850. Or experience Cape Cod charm in the Carriage House, the smallest outbuilding on the Inn at Duck Creeke complex, a Wellfleet icon (508-349-9333, www.innatduckcreeke.com)