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Overview
U-shaped spur-and-groove reef 5 miles south of Big Pine Key, named after the 44-gun HMS Looe — a British man-of-war that ran aground here in February 1744 while towing a captured French ship. Anchor, ballast pile, and copper plating from the wreck still lie on the eastern end in 25 feet of water. The 374-acre Sanctuary Preservation Area is renowned for one of the densest surviving stands of elkhorn coral in the Florida Reef Tract, with parallel coral fingers and sand grooves dropping from 7 to 35 feet. Reliable encounters with goliath grouper under ledges, tarpon, large schools of grunts and yellowtail snapper, and seasonal nurse sharks. Hosts the annual Underwater Music Festival in July, when speakers are lowered to the reef.
Briefing note
Sanctuary Preservation Area inside Florida Keys National Marine Sanctuary — mooring buoys only, no anchoring, no fishing, no spearfishing, no coral contact, no glove use. Reef-friendly sunscreen required. The annual Lower Keys Underwater Music Festival is held in early July. Current on the outer reef edge can run moderately; back reef shallows are usually calm enough for snorkelers and open-water divers.
What you'll see
10 species curated- year-roundElkhorn coral
- year-roundStaghorn coral
- year-roundGoliath grouper
- seasonalAtlantic tarponPeak: Apr · May · Jun · Jul
- year-roundYellowtail snapper
- year-roundFrench grunt
- seasonalNurse sharkPeak: May · Jun · Jul · Aug · Sep
- year-roundHogfish
- year-roundQueen angelfish
- year-roundGreen moray
Sightings evidence
1 record on file- high confidenceElkhorn coral
- Last confirmed
- May 2026
- Recent records
- 130 within 10 km
Sources & methodology
How we summarise this
We aggregate confirmed occurrence records from GBIF and OBIS within a fixed radius of each dive site. Occurrence records confirm presence and reveal seasonality clustering, but they DO NOT measure per-dive probability — there is no eligible-effort denominator. We deliberately do not publish a numeric '% chance of sighting' from this data.
Sources
- Global Biodiversity Information Facility — GBIF Secretariat
- Ocean Biodiversity Information System — IOC-UNESCO
- OBIS-SEAMAP — Duke University Marine Geospatial Ecology Lab / OBIS
- iNaturalist — California Academy of Sciences & National Geographic Society
- IUCN Red List of Threatened Species — International Union for Conservation of Nature
- WoRMS — World Register of Marine Species — Flanders Marine Institute (VLIZ)
- FishBase — FishBase Consortium
- Atlas of Living Australia — CSIRO / GBIF Australia
- REEF Volunteer Fish Survey — Reef Environmental Education Foundation
Conditions
| Month | Water | Visibility | Current |
|---|---|---|---|
| Jan | 21–23 °C | 12–22 m | mild |
| Feb | 21–23 °C | 12–22 m | mild |
| Mar | 23–25 °C | 15–25 m | mild |
| Apr | 24–26 °C | 18–28 m | mild |
| May | 26–28 °C | 20–30 m | mild |
| Jun | 28–30 °C | 20–30 m | mild |
| Jul | 29–30 °C | 20–30 m | mild |
| Aug | 29–31 °C | 18–28 m | mild |
| Sep | 28–30 °C | 15–25 m | mild |
| Oct | 26–28 °C | 15–25 m | mild |
| Nov | 24–26 °C | 12–22 m | mild |
| Dec | 22–24 °C | 12–22 m | mild |
Season calendar
Peak season highlighted · current month outlined
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