Key West · United States · Reef
Rock Key
Unusually deep, wide reef crevices that hide grouper and morays
Photo: SNORKELINGDIVES.COM · CC BY 2.0
Rock Key is a coral reef inside the Florida Keys National Marine Sanctuary, southwest of Key West between Sand Key and Eastern Dry Rocks. What sets it apart is the shape of the reef: its crevices are deeper and wider than on most coral reefs, and those openings are where grouper, moray eels and other Florida fish hide. The summit runs from 1 to 35 ft (0.3 to 11 m), so it is a shallow boat dive with plenty to look into.
Where it is and how deep
24.4550° N, 81.8583° WPublished position for this site.
The dive
Drop onto the reef and find your depth: the summit sits between 1 and 35 ft (0.3 and 11 m), so there is no descent to speak of and the dive is spent moving slowly along the coral. The thing to do at Rock Key is to slow down at every gap. The crevices within the reef are deeper and wider than what is usually found at other coral reefs, and these wider openings make the hiding habitat for grouper, moray eel and other Florida fish, so the rewards come from putting your torch into the dark rather than from covering distance.
Rock Key lies inside the Florida Keys National Marine Sanctuary and the Key West National Wildlife Refuge. Older guides call it a Sanctuary Preservation Area, but the sanctuary's 2025 Restoration Blueprint rule eliminated the Rock Key SPA, so do not rely on the old zone rules. The reef is close enough to Sand Key and Eastern Dry Rocks that boats combine them on a single outing, and the dive ends the way it began, with an easy ascent from shallow coral back to the boat.
Marine life and season
- Groupers
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Fair | Fair | Good | Prime | Prime | Good | Good | Good | Fair | Fair | Good | Good |
Season follows Key West: November-April is the dry season, but winter cold fronts bring the coolest water (23 C) and the lowest sourced visibility; the wet season runs May-October and storm risk peaks in September.
Photos from Rock Key
SNORKELINGDIVES.COM · CC BY 2.0
SNORKELINGDIVES.COM · CC BY 2.0
SNORKELINGDIVES.COM · CC BY 2.0
Questions divers ask
What makes Rock Key different from the other Key West reefs?+
Its crevices are deeper and wider than on most coral reefs, and those openings shelter grouper, moray eels and other Florida fish, so the dive is about looking into the reef rather than swimming over it.
Is Rock Key a Sanctuary Preservation Area?+
Not any more. The Rock Key SPA was one of the zones eliminated by the Florida Keys National Marine Sanctuary's 2025 Restoration Blueprint rule; the reef remains inside the sanctuary.
Sources
Photo credits
- A hogfish close up over the coral crevices of Rock Key by SNORKELINGDIVES.COM, CC BY 2.0, via Openverse
- A stoplight parrotfish swimming down over coral at Rock Key by SNORKELINGDIVES.COM, CC BY 2.0, via Openverse
- A speckled filefish hovering over the reef at Rock Key by SNORKELINGDIVES.COM, CC BY 2.0, via Openverse
- A green and orange stoplight parrotfish grazing on coral at Rock Key by SNORKELINGDIVES.COM, CC BY 2.0, via Openverse
More dive sites in Key West
Goliath grouper and turtles on a 5-9 m reef fifteen minutes from town
Reef
Fields of coral drifted to 18 m with goliath grouper and sharks
Goliath grouper inside a 56 m hull that sank under tow in 1985, upright at 27 m
Coral fingers and sand canyons on an SPA reef a mile east of Sand Key light
Swim through needle-shaped coral heads on a spur-and-groove outer reef
An eroded island's sand patch ringed by shallow reef under Sand Key Light
The world's second-largest artificial reef, sunk in 2009
Hundreds of sea fans and unhunted grouper in a fully no-take reserve
Similar dives elsewhere
A nine-foot bronze figure standing in 7.6 m of water
Winding channels and swim-throughs inside a protected reef
A reef crest that breaks the surface at low tide
Sea lions in 3 to 9 metres, on a rock bottom with no coral.