French Reef
Florida Keys · United States
Six miles southeast of Key Largo inside the Florida Keys National Marine Sanctuary, French Reef is the cave network of the upper Keys. Three large caverns named Christmas Tree Cave, Sand Bottom Cave, and Hourglass Cave cut through the spur and groove formations between 5 and 12 metres, packed with shimmering schools of glassy sweepers and the occasional resident green moray. The shallow reef carries elkhorn and brain coral, Christmas tree worms erupt from the coral heads, and southern stingrays, nurse sharks, and eagle rays patrol the sand channels. French Deep on the southeast corner drops past 25 metres into deeper water for a wall style finish.
Conditions
Depth
5 to 30 m
Open water and up
Current
Usually gentle
Can pick up on the edge
Visibility
22 to 30 m
Clearest in the calm season
Water
22 to 30°C
3 mm shorty
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 22 | 22 | 23 | 24 | 25 | 27 | 28 | 28 | 28 | 26 | 24 | 22 |
| Vis (m) | 12 | 12 | 15 | 18 | 20 | 20 | 22 | 22 | 18 | 15 | 12 | 12 |
| Current | Gentle | Gentle | Gentle | Gentle | Gentle | Gentle | Gentle | Gentle | Gentle | Gentle | Gentle | Gentle |
Your chances of seeing each animal
Glassy sweeper
Last confirmed May 15, 2026 · 130 records
Almost always
Nearly every dive
Nurse shark
Last confirmed May 24, 2026 · 98 records
Almost always
Nearly every dive
Hogfish
Last confirmed Jul 8, 2026 · 86 records
Almost always
Nearly every dive
Stoplight parrotfish
Last confirmed Jul 4, 2026 · 227 records
Almost always
Nearly every dive
Sergeant major
Last confirmed Jun 29, 2026 · 149 records
Almost always
Nearly every dive
Great barracuda
Last confirmed Jul 4, 2026 · 222 records
Almost always
Nearly every dive
Southern stingray
Last confirmed Jul 4, 2026 · 52 records
Almost always
Nearly every dive
Christmas tree worm
Last confirmed Jun 15, 2026 · 33 records
Very likely
Most dives
Gear