United States · Florida

Florida Keys

Warm-water reef season before winter cold fronts become more common.

The Florida Keys offer the US's most accessible reef and wreck diving — the Christ of the Abyss statue, the USS Spiegel Grove and USS Vandenberg artificial reef wrecks, plus living coral reef tract from Key Largo to Key West.

Good season

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Year-round; May–September is warmest. Hurricane risk June–November.

Trip duration

3–7 nights with rental car along the Keys.

Dive style

Boat diving on reef and wreck; mild-to-moderate current.

Dive level

Open Water for most reef; Advanced for the deeper wrecks (30m).

Reef health

What you’ll actually find
Severely degraded

This reef has lost most of its live coral. Fish life and topography may still be worth diving, but expect a very different reef from the older photos.

Coral reef health

How is this calculated?
A decade ago
Survey 2014
24%
Today
Survey 2024
13%

On current trend, no live coral by ~2036. Losing about 1.1% cover per year — roughly 12 years of reef left to see if nothing changes.

Heat stress right now

No stress

No abnormal heat right now. Corals stay coloured.

NOAA Coral Reef Watch · updated May 2026 · 0 °C-week heat dose

What to expect on a dive

Florida Keys reefs have lost the majority of their hard coral over two decades and were hit hard by 2023's marine heatwave. Wrecks and fish life still excellent.

Sources, methodology, and the raw numbers

Raw observed numbers

  • Coral cover: 13% (survey Sep 2024, NOAA NCRMP Florida Keys monitoring)
  • Bleached: 28%
  • Recent mortality: 13%
  • Florida Keys — observed condition reflects the severe decline regional pattern.

Raw thermal numbers

  • NOAA CRW alert level: No stress
  • Degree Heating Weeks: 0 °C-wk
  • SST anomaly: +1.9 °C

How we summarise this

Observed coral cover, bleaching, and mortality come from named in-situ surveys with a stated date and method — they describe one snapshot of one reef and do not extrapolate to neighbouring sites. Current thermal stress is satellite-derived from NOAA Coral Reef Watch at ~5 km resolution; it indicates risk, not observed coral damage. We deliberately separate observed condition, current thermal stress, and projection — and we never publish a projection without a documented model and uncertainty.

Sources

Reef condition changes year to year. If you visit, consider supporting responsible-travel and conservation operators on the ground.

Pressure on this reef

Protection · fishing · what you can do

Protected-area status

Strict MPA

Inside a strict marine protected area with active enforcement.

Fishing pressure

Moderate fishing pressure

Dominant pressures

  • agricultural runoff from south Florida
  • SCTLD
  • warming
  • tourism

4 Green Fins-verified operators known at this location.

What you can do

Florida Keys National Marine Sanctuary protects the reef but can't protect the water flowing from the Everglades. Choose restoration-affiliated operators and pay the sanctuary fee.

Protection status sourced from Protected Planet / WDPA and refined with Marine Protection Atlas. Fishing pressure proxy is Global Fishing Watch AIS data. See the methodology for what these sources can and can’t prove.

Pollution & water-quality

What divers should know
  • SCTLD coral disease outbreak

    SEVERE

    Since 2014

    Stony coral tissue loss disease has affected over half of Florida's reef-building coral species. Brain corals, star corals, and pillar corals have been hit hardest. Active treatment programs are ongoing at major sites.

  • Agricultural runoff from south Florida

    CONCERNING

    Since ongoing

    Nutrient-laden freshwater from sugar plantations and the Everglades chronically degrades reef-flat water clarity, especially after summer rains.

High microplastics

What this means for your trip

Choose offshore sites and wall dives over inshore patch reefs for the best visibility. Many operators participate in coral-restoration nurseries — ask about joining a fragment-outplanting dive.

Dive sites here

6 curated

Gear

What to bring

Basic kit

Site-specific add-ons

Some dive sites here call for extra gear. Check the individual site page for full context.

  • Dive lightInterior compartments are dark and silt-prone. · USS Vandenberg
  • Wreck-trained guidePenetration sections require formal training. · USS Vandenberg
  • Underwater cameraIconic photo subject — even smartphone housings deliver here. · Christ of the Abyss
  • SMB and reelGulf Stream current can push divers off the wreck during ascent; deploy a marker for boat pickup. · USCGC Duane
  • Dive computer with deco modelingDeck-level depth at 27-30 m and bottom time on the wreck routinely push recreational no-deco limits. · USCGC Duane
  • Nitrox certification recommendedEAN32 significantly extends bottom time at the deeper deck and stern. · USCGC Duane

What divers say

The Vandenberg is one of the great Americas wreck dives. Two days isn't enough to see all of it.
Wreck diver