Three Fathom Wall
Dive site at a Cayman Islands Department of Environment public mooring. Here's what has been recorded at this site month by month, how the region’s reefs have weathered ocean heat, and how to prepare.
Three Fathom Wall: dive site at a Cayman Islands Department of Environment public mooring.
Entry
Shore and boat entries vary by site. We list only rules we can cite from official sources; entry points, depths and currents will be added once we can verify them.
- The DoE has installed public moorings to protect reefs from anchor damage. Use a mooring instead of anchoring whenever possible; it is an offence to damage coral anywhere in Cayman waters. Cayman Islands DoE · Public Moorings
- The maximum stay on a public mooring is 3 hours. Do not use moorings in winds of 25 knots or more. Cayman Islands DoE · Public Moorings
- Marine Park zones carry their own rules (for example, no taking of marine life in Marine Reserve zones and no SCUBA diving in No Diving zones without permission). Check the zone with the DoE app or brochures. Cayman Islands DoE · Marine Parks
- Wildlife Interaction Zones are the only places in the Cayman Islands where you may legally feed or interact with marine life. Cayman Islands DoE · Marine Manners
Near this sitegeotagged about 3.0 km from the site coordinates Hogfish (Lachnolaimus maximus) · desertnaturalist · CC BY 4.0 · iNaturalist
The surface noise falls away.
Reds go first. The world turns blue-green.
Then Three Fathom Wall rises to meet you.
What lives here, by month
Pick a month. These are the species most often recorded within about a kilometre in that month, from open survey records.
Most-recorded species, all months
- Boulder star coral (115)
- Boulder star coral (106)
- Great Star Coral (77)
- Finger Coral (56)
- Bumpy star coral (54)
- Massive Starlet Coral (42)
- Mustard Hill Coral (30)
- Lettuce Coral (20)
- Symmetrical brain coral (20)
- Grooved brain coral (16)
- Blue Tang (10)
- Bluehead Wrasse (9)
- Brown Chromis (8)
- Black triggerfish (7)
- Royal Gramma (6)
- Blue Chromis (6)
- Yellowtail Snapper (5)
- Striped Parrotfish (5)
- Stoplight Parrotfish (5)
- Boulder brain coral (4)
GBIF.org (2026-10-15), occurrence records within ~1 km, licensed CC0 or CC BY 4.0 only. Birds and land animals are excluded. Counts reflect survey effort, not abundance. 997 qualifying records. See them on GBIF. Common names: Wikidata (CC0) / GBIF. Species photos: Wikimedia Commons, credited with each species.
Forty-one summers of heat
Each stripe is one year since 1985, colored by its peak heat stress across NOAA's “Cayman Islands” region. These are NOAA Coral Reef Watch satellite figures for the whole region, not for this one site.
Heat stress, measured from orbit.
NOAA CRW virtual station “Cayman Islands”. NOAA's alert thresholds are 4 °C-weeks (Alert Level 1) and 8 °C-weeks (Alert Level 2). Station page · Method. Credit: NOAA Coral Reef Watch.
Conditions
Average sea temperature through the year. Check the live readings before you go.
Average sea surface temperature by month: NOAA CRW “Cayman Islands” station climatology (monthly means).
Buoy readings are measurements; forecasts are models. Use them for planning only, and assess conditions on site. Depth and visibility data aren't listed until we can cite a source.
Plan & prepare
- Read the official marine forecast the night before.Offshore, wind and sea state decide the day.
- Check the cited local rules above and pay any park fee before you dive.[Placeholder: verified operator list to come]
- Study this month's species above.You'll recognise more when you know the names.
- Hands off, fins up, buoyancy dialled. Log what you see.Your sightings can become tomorrow's open data.
Credits
- Coordinates
- Cayman Islands DoE public mooring “Three Fathom Wall” (Little Cayman, January 2023) · source · Cayman Islands Government, public data. Cayman Islands Department of Environment, Little Cayman and Cayman Brac public moorings (GPX, January 2023). Each site uses its named mooring; the Bloody Bay Wall sites are moorings along that wall.
- Species records
- GBIF.org, CC0 & CC BY 4.0 records. By license: CC_BY_4_0: 994, CC0_1_0: 3
- Dataset
- Atlantic and Gulf Rapid Reef Assessment - Benthic · doi:10.15468/vmcydh (678 records) · GBIF
- Dataset
- iNaturalist Research-grade Observations · doi:10.15468/ab3s5x (238 records) · GBIF
- Dataset
- EOD – eBird Observation Dataset · doi:10.15468/aomfnb (77 records) · GBIF
- Dataset
- Delaware Museum of Nature and Science – Mollusks · doi:10.15468/lfwzak (1 records) · GBIF
- Dataset
- Birda - Global Observation Dataset · doi:10.15468/6kud7x (1 records) · GBIF
- Dataset
- NMNH Extant Specimen Records (USNM, US) · doi:10.15468/hnhrg3 (1 records) · GBIF
- Dataset
- SIO Marine Vertebrate Collection · doi:10.15468/ad1ovc (1 records) · GBIF
- Query
- https://api.gbif.org/v1/occurrence/search?decimalLatitude=19.674916999999997,19.694917&decimalLongitude=-80.08800000000001,-80.068&license=CC0_1_0&license=CC_BY_4_0&taxonKey=44&taxonKey=206&taxonKey=229&taxonKey=136&taxonKey=225&occurrenceStatus=PRESENT&limit=0
- Heat stress & SST
- NOAA Coral Reef Watch, 5 km Regional Virtual Station “Cayman Islands”
- Hero photo
- Near this sitegeotagged about 3.0 km from the site coordinates Hogfish (Lachnolaimus maximus) · desertnaturalist · CC BY 4.0 · iNaturalist
- Species photos
- Wikimedia Commons, credited with each species. Full list: Data & sources