Branching Anemone (Lebrunia neglecta)
A dive briefing · Grand Cayman, Cayman Islands

Tarpon Tunnels

Dive site at a Cayman Islands Department of Environment public mooring off Grand Cayman. 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.

Grand Caymanwall
At this sitegeotagged 488 m from the site coordinates Branching Anemone (Lebrunia neglecta) · Dan Schofield · CC BY 4.0 · iNaturalist
Dog Snapper (Lutjanus jocu)
Chapter I · Arrival

Tarpon Tunnels: dive site at a Cayman Islands Department of Environment public mooring off Grand Cayman.

19.387° N81.338° W · Cayman Islands DoE public moorings 2023
113open records · GBIF
49species recorded
At this sitegeotagged 707 m from the site coordinates Dog Snapper (Lutjanus jocu) · Dan Schofield · CC BY 4.0 · iNaturalist
II

Entry

Dog Snapper (Lutjanus jocu)

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.

To verifyDepth range, entry points and current notes. We publish them only with a citation. The coordinates mark the site in general, not a mooring or entry point.
Local rules (cited)
  • 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

At this sitegeotagged 707 m from the site coordinates Dog Snapper (Lutjanus jocu) · Dan Schofield · CC BY 4.0 · iNaturalist

▶
Captain's footage: Tarpon Tunnels
[video slot · coming soon]

The surface noise falls away.

Reds go first. The world turns blue-green.

Then Tarpon Tunnels rises to meet you.

Branching Anemone (Lebrunia neglecta)
IV

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.

Oct
October · 1 qualifying records
Life calendar · records per month for this site's most-recorded species (blank means not in that month's top list)
SpeciesJanFebMarAprMayJunJulAugSepOctNovDec
Mutton snapper
Phallusia fragilis
Nurse shark
Queen Angelfish
Black triggerfish
Cero
Blue runner
Green moray
Stoplight Parrotfish
Common Lionfish
Dog snapper
French angelfish

Most-recorded species, all months

  1. Mutton snapper (8)
  2. Phallusia fragilis (6)
  3. Nurse shark (5)
  4. Cero (4)
  5. Blue runner (4)
  6. Stoplight Parrotfish (4)
  7. Green moray (4)
  8. Black triggerfish (4)
  9. Queen Angelfish (4)
  10. Common Lionfish (3)
  11. Margate (3)
  12. Dog snapper (3)
  13. French angelfish (3)
  14. Blue parrotfish (3)
  15. Permit (3)
  16. Great Star Coral (2)
  17. Porkfish (2)
  18. Tiger grouper (2)
  19. Striped Parrotfish (2)
  20. Trunkfish (2)

GBIF.org (2026-10-14), 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. 113 qualifying records. See them on GBIF. Common names: Wikidata (CC0) / GBIF. Species photos: Wikimedia Commons, credited with each species.

V

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.

19852026
Reef health report · Cayman Islands

Heat stress, measured from orbit.

Degree Heating Weeks · 2026-10-1311.9°C-weeks · NOAA status: Bleaching Watch

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.

Peak per year · dashed lines at 4, 8 and 16 °C-weeks
The past twelve months
VI

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.

VII

Plan & prepare

  1. Read the official marine forecast the night before.Offshore, wind and sea state decide the day.
  2. Check the cited local rules above and pay any park fee before you dive.[Placeholder: verified operator list to come]
  3. Study this month's species above.You'll recognise more when you know the names.
  4. Hands off, fins up, buoyancy dialled. Log what you see.Your sightings can become tomorrow's open data.

Credits

Coordinates
Cayman Islands DoE public moorings 2023 (NORTH), mooring "Tarpon Tunnels" · source · government publication. Cayman Islands Department of Environment, Public Moorings (updated January 2023). Each site uses the coordinates of the named public mooring.
Species records
GBIF.org, CC0 & CC BY 4.0 records. By license: CC_BY_4_0: 108, CC0_1_0: 5
Dataset
iNaturalist Research-grade Observations · doi:10.15468/ab3s5x (101 records) · GBIF
Dataset
EOD – eBird Observation Dataset · doi:10.15468/aomfnb (8 records) · GBIF
Dataset
NMNH Extant Specimen Records (USNM, US) · doi:10.15468/hnhrg3 (4 records) · GBIF
Query
https://api.gbif.org/v1/occurrence/search?decimalLatitude=19.376932999999998,19.396933&decimalLongitude=-81.34815,-81.32815&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
At this sitegeotagged 488 m from the site coordinates Branching Anemone (Lebrunia neglecta) · Dan Schofield · CC BY 4.0 · iNaturalist
Arrival photo
At this sitegeotagged 707 m from the site coordinates Dog Snapper (Lutjanus jocu) · Dan Schofield · CC BY 4.0 · iNaturalist
Gallery
5 photos, credited under each image
Species photos
Wikimedia Commons, credited with each species. Full list: Data & sources