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Overview
A 100 m Treasury-class US Coast Guard cutter scuttled 1 mile south of Molasses Reef off Key Largo on 27 November 1987 as an artificial reef. Commissioned in 1936, she escorted North Atlantic convoys in WWII, helped sink U-boat U-77, then served in Vietnam and on drug interdiction before retirement in 1985. The wreck sits perfectly upright on a sandy bottom at 37 m — the mast and crow's nest reach up to 18 m, the bridge sits at 23 m, and the main deck runs 27-30 m. Gulf Stream current along the outer reef line draws schooling barracuda, jacks, and resident goliath grouper sheltering under the stern; eagle rays and the occasional bull shark cruise the deeper sand. Added to the National Register of Historic Places in 2002. The visible flag at the masthead is the canonical photo subject.
Briefing note
Advanced Open Water and 25+ logged dives recommended; current can run strong, especially in late summer when the Gulf Stream presses closer to the reef line. Three mooring buoys mark the bow, midships, and stern — never tie to the wreck. National Register of Historic Places — no artifact removal. Penetration into the engine room and lower decks is possible but silt-prone and requires wreck-penetration training. The flag at the mast top is regularly replaced by local dive operators.
What you'll see
7 species curated- year-roundGoliath grouper
- year-roundGreat barracuda
- year-roundAtlantic spadefish
- seasonalSpotted eagle rayPeak: Apr · May · Jun · Jul · Aug · Sep · Oct
- year-roundHorse-eye jack
- rareBull shark
- year-roundGreen moray
Sightings evidence
1 record on file- high confidenceGoliath grouper
- 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 We deliberately do not publish a numeric '% chance of sighting' from this data.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
The wreck
Ship history- National marine sanctuary
Warship · United States
USCGC Duane
- Built
- 1936
- Sunk
- Nov 27, 1987
- Length
- 100 m
- Tonnage
- 2,350
- Diveable depth
- 18–37 m
- How she sank
- Scuttled as artificial reef
Treasury-class US Coast Guard cutter scuttled off Molasses Reef as an artificial reef after 51 years of service. Sits upright; the bridge and engine room are accessible.
Notable features
- intact bridge
- engine room
- crow's nest at 18 m
- barracuda schools
Vessel histories sourced from the Naval History and Heritage Command (DANFS), NOAA ENC Direct, and editorial research. Bathymetry per GEBCO. See the methodology for limits.
Conditions
| Month | Water | Visibility | Current |
|---|---|---|---|
| Jan | 22–24 °C | 15–25 m | moderate |
| Feb | 22–24 °C | 15–25 m | moderate |
| Mar | 23–25 °C | 20–30 m | moderate |
| Apr | 24–26 °C | 25–35 m | moderate |
| May | 26–28 °C | 25–40 m | moderate |
| Jun | 28–29 °C | 25–40 m | moderate |
| Jul | 29–30 °C | 25–40 m | moderate |
| Aug | 29–31 °C | 25–40 m | moderate |
| Sep | 28–30 °C | 20–30 m | strong |
| Oct | 26–28 °C | 20–30 m | moderate |
| Nov | 24–26 °C | 15–25 m | moderate |
| Dec | 22–24 °C | 15–25 m | moderate |
Season calendar
Peak season highlighted · current month outlined
Gear for this site
Beyond the basic kit- SMB and reel — Gulf Stream current can push divers off the wreck during ascent; deploy a marker for boat pickup.
- Dive computer with deco modeling — Deck-level depth at 27-30 m and bottom time on the wreck routinely push recreational no-deco limits.
- Nitrox certification recommended — EAN32 significantly extends bottom time at the deeper deck and stern.
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