A dive briefing · Belize Barrier Reef & atolls, Belize

Great Blue Hole

Dive site on the Belize Barrier Reef or its offshore atolls. 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.

Belizeblue hole

At this site Belize Blue Hole · The TerraMar Project · CC BY 2.0 · Wikimedia Commons

Chapter I · Arrival

Great Blue Hole: dive site on the Belize Barrier Reef or its offshore atolls.

~17.316° N~87.534° W · Wikidata

45open records · GBIF

18species recorded

At this site Belize Blue Hole (TMP) · The TerraMar Project · CC BY 2.0 · Wikimedia Commons

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.

Approximate positionThese coordinates come from a crowd-sourced map or Wikidata item, not an official mooring list. Use them for orientation only.

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)

Hol Chan Marine Reserve: you may dive and snorkel in the recreational zones only after registering and being briefed on the reserve rules; scuba only if you are certified or on a course run by a certified instructor. Belize Fisheries Department · Hol Chan Marine Reserve
Hol Chan: fishing and feeding fish are prohibited, gloves are prohibited, and no gear other than fins and mask is allowed. Belize Fisheries Department · Hol Chan Marine Reserve
Scuba diving is prohibited within the exclusive recreational area of Shark Ray Alley. Belize Fisheries Department · Hol Chan Marine Reserve

At this site Belize Blue Hole (TMP) · The TerraMar Project · CC BY 2.0 · Wikimedia Commons

The surface noise falls away.

Reds go first. The world turns blue-green.

Then Great Blue Hole rises to meet you.

Belize Blue Hole

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 · 2 qualifying records

Life calendar · records per month for this site's most-recorded species (blank means not in that month's top list)

Species	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Bluehead Wrasse
White Grunt
Sergeant Major
Common sea fan
Blue Tang
Southern Stingray
Caribbean reef squid
Schoolmaster Snapper
Massive Starlet Coral
Bermuda Chub
Bass Seachub
Bluestriped Grunt

Most-recorded species, all months

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. 45 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 “Belize” region. These are NOAA Coral Reef Watch satellite figures for the whole region, not for this one site.

19852026

Reef health report · Belize

Heat stress, measured from orbit.

Degree Heating Weeks · 2026-10-1314.8°C-weeks · NOAA status: Alert Level 2

NOAA CRW virtual station “Belize”. 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

Conditions

Average sea temperature through the year. Check the live readings before you go.

Average sea surface temperature by month: NOAA CRW “Belize” station climatology (monthly means).

National Meteorological Service of Belize · forecasts →

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

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.

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Photographs from Great Blue Hole

Openly licensed photos, each checked for location against its title, description, category or geotag. Labels show how close each one is to the site.

**Blue Hole coral**At this site jayhem · CC BY 2.0 · Wikimedia Commons

**Brain Coral, Belize**At this site jayhem from Antibes, France · CC BY-SA 2.0 · Wikimedia Commons

**Great Blue Hole, Belize (ASTER)**At this site NASA/METI/AIST/Japan Space Systems, and U.S./Japan ASTER Science Team · Public domain · Wikimedia Commons

**Lighthouse Reef Belize**At this site Jesse Allen · Public domain · Wikimedia Commons

**Pozo Azul San Pedro del rio Tachira**At this site Imindiola · CC BY-SA 3.0 · Wikimedia Commons

**The Great Blue Hole, Belize**At this sitegeotagged 338 m from the site coordinates SentinelHub · CC BY 2.0 · Wikimedia Commons

**Great Blue Hole Belize**At this sitegeotagged 875 m from the site coordinates Axelspace Corporation · CC BY-SA 4.0 · Wikimedia Commons

Credits

Coordinates: Wikidata Q86486 (CC0). Wikidata (CC0) and OpenStreetMap (ODbL) features. These are approximate positions, not official mooring coordinates.
Species records: GBIF.org, CC0 & CC BY 4.0 records. By license: CC_BY_4_0: 45
Dataset: iNaturalist Research-grade Observations · doi:10.15468/ab3s5x (27 records) · GBIF
Dataset: EOD – eBird Observation Dataset · doi:10.15468/aomfnb (18 records) · GBIF
Query: https://api.gbif.org/v1/occurrence/search?decimalLatitude=17.30556,17.325560000000003&decimalLongitude=-87.54444000000001,-87.52444&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 “Belize”
Hero photo: At this site Belize Blue Hole · The TerraMar Project · CC BY 2.0 · Wikimedia Commons
Arrival photo: At this site Belize Blue Hole (TMP) · The TerraMar Project · CC BY 2.0 · Wikimedia Commons
Gallery: 7 photos, credited under each image
Species photos: Wikimedia Commons, credited with each species. Full list: Data & sources