Snorkeling the Sunken Fort at Egmont Key

In 1898 the Army built Fort Dade on Egmont Key with gun batteries set a safe 300 feet inland from the beach. The Gulf had other plans. The island has lost roughly half its landmass since 1875, and today two of those batteries sit 300-plus feet offshore, underwater — intact enough to swim over, strange enough to be worth the trip on their own.

What you're actually swimming over

Batteries Page and Burchsted: poured-concrete gun platforms, walls, and steps, now doubling as artificial reef off the island's southwest side. Sheepshead and snapper hold in the shadows, rays work the sand between the structures, and on a clear day the geometry reads from the surface — right angles where the Gulf shouldn't have any.

How to do it from a rental boat

• Anchor well off the ruins in the sand, never on the structures, and swim over. Watch the current — this is the open mouth of Tampa Bay, so time it for slack tide.
• Bring your own mask, snorkel, and fins — there's no rental shack on an island with no road.
• Fly a dive flag if you have one and keep a lookout aboard; the pass gets boat traffic on weekends.
• Calm, light-wind mornings give the best visibility — spring through early fall is prime.

The dry half of the trip

Beach the crew on the open north end afterward: brick roads through the palms, the walkable ruins in the island's interior, the 1858 lighthouse (photo stop only — it's closed to entry), and gopher tortoises commuting across the paths. The southern third of the island is a closed bird sanctuary — no landing, no shortcuts, patrolled. Full island rundown: the Egmont Key guide.

Booking it

This is a ¾ Day or Full Day trip — the run to the mouth of the bay plus a snorkel plus beach time doesn't fit in four hours. If you're weighing the ferry instead, read the ferry-vs-your-own-boat math first: the ferry doesn't wait while you snorkel.

Masks packed? Grab a calm-morning date and we'll mark the route at the dock.