We roll onto 10-mile-long Marathon as the last faint pink from the sky is ebbing away, wondering what the next day’s dives will deliver along with where to feast on the island’s fresh seafood. Isn’t eating always top of mind for a diver out of water?

Going on a divemaster’s tip (they know the best spots) we make for Castaway Waterfront Restaurant & Sushi Bar, hidden on a narrow canal where manatees frolic. We do our part to dine with the reef’s best interest in mind by ordering the lionfish sushi roll, made famous here by owner John Mirabella. A diver himself, he pulls up a chair and shares with us the island’s unique appeal. “I wanted to be where the water is clear and the people are friendly,” he says. The island is famous among anglers and known as a family-friendly stop, with its laid-back residents and abundant parks. Divers know Marathon for one very special wreck, the Thunderbolt, a 188-foot-long former World War II cable laying ship that’s among the oldest wrecks in the Keys. It was purpose-sunk in 1986 in about 120 feet of water and attracts schooling fish such as amberjacks and, come summer, migrating tarpon.

On this day, we’re bound for a smaller but no less fishy hunk of rusting metal, Flagler’s Barge, which sits in just 25 feet of water and is carpeted with sunset-hued sponges that glow pink, yellow, orange and purple in the dappled sunbeams. The wreck’s wide-open ribs make for fun little swim-throughs everywhere we fin. Yellowtail snappers and blue tangs school so thick it’s tempting to wave my hand like a windshield wiper to swim through, but I resist the temptation and just enjoy floating within the colorful vortexes they create. A slipper lobster and a tiny moray in the wreck’s never-ending nooks and crannies keep me entranced till it’s time to surface. A second tank on Sombrero Reef reveals beautiful stands planted by coral restoration groups, including the healthiest little grove of elkhorn coral I’ve seen in ages. “People are surprised that Sombrero is so full of life because it’s so shallow,” says Lisa Flanery, our dive instructor with Tilden’s Scuba Center, when we surface. “The coral and fish are everywhere, often in just 10 feet of water, and the coral structures are so tall.”

Back at Isla Bella Marina, where the dive boat docks, we’re steps from our comfortable rooms at the oceanfront hotel with the same name. It’s tempting to make for a hot shower. But the full moon is just starting to rise and there’s time to paddle one of the resort’s kayaks in the day’s last light.

MUST STAY: Isla Bella Beach Resort is worth the splurge for rooms that are all oceanfront, palms strung with hammocks and a gorgeous waterfront beach bar.

MUST EAT: Lighthouse Grille has the prettiest bayside views for sunset, and Cuban rice balls as tasty as anything in Havana. Get your Jamaican jerk fix at Irie Island Eats, hidden right off the Overseas Highway in a garden overflowing with tropical plants.

MUST DIVE, WRECK: Light penetration is allowed on the Thunderbolt, a former WWII cable-laying ship sunk as an artificial reef in 1986 that has decades of lush coral growth to show for it.

MUST DIVE, REEF: Sombrero Reef is as shallow as it is fishy; hourlong bottom times fly by with so many critters and schooling fish to ogle.

Explore all stops on the Ultimate Scuba Road Trip through the Florida Keys:
Key Largo | Islamorada | Big Pine Key | Key West