Reef data
What’s live, what’s a snapshot, what we can’t see
scubaSeason mixes daily satellite data with much older in water survey snapshots. The labels next to every reef number on the site tell you which is which. This page lays out the whole picture.
What’s live every day
NOAA Coral Reef Watch · 5 km · v3.1
- Bleaching Alert Area (no stress / watch / warning / alert 1 / alert 2).
- Degree Heating Weeks (°C weeks of accumulated heat).
- SST anomaly vs. climatology (°C).
Pulled nightly from NOAA’s public ERDDAP endpoint against the lat/lng of every reef location on the site. Public domain, no API key. NOAA Coral Reef Watch →
What’s a snapshot
Coral cover, bleaching %, and historical baselines come from in water surveys done by reef monitoring programs. They’re not updated continuously. The freshness varies by region — and that variance is itself a fact worth knowing before you read the number.
| Region | Earliest reliable baseline |
|---|---|
| Great Barrier Reef (Australia) AIMS Long Term Monitoring Program — the longest continuous reef survey record on Earth, going back to 1986. Annual cover updates per sector. | 1986 |
| Florida Keys & Caribbean US NOAA NCRMP + earlier Florida Reef Tract programs. Coverage solid since the mid 1990s; AGRRA fills wider Caribbean from ~1998. | 1995 |
| US Pacific (Hawaiʻi, Marianas, American Samoa) NCRMP Pacific cycle began in 2012. Earlier site level data exists but isn't standardized into a continuous time series. | 2012 |
| Indo Pacific (most sites) Most Indo Pacific reefs outside named jurisdictions only have a baseline from the start of the Third Global Coral Bleaching Event (2014–2017), when international monitoring effort spiked. For many sites that's the first quantitative measurement on record. | 2014 |
| Western Indian Ocean & many remote reefs Some sites have one survey ever. Treat the displayed cover as a single observation, not a trend. | Single survey |
Why 2014?It’s when the Third Global Coral Bleaching Event (2014–2017) pulled international monitoring attention to reefs that had never been systematically surveyed before. For a lot of Indo Pacific sites, that’s literally the first numeric observation on file. Older “before” values for those reefs don’t exist — not because nothing happened before 2014, but because nobody was measuring.
What we can’t see today
Things people ask about that we deliberately don’t claim, because the data isn’t there yet or isn’t resolved at site scale:
- Water clarity / turbidityat site resolution — global satellite products exist but don’t resolve a single reef.
- Ocean acidification at the dive site scale — we have basin wide pH trends, not site by site values.
- Fish populationsand biomass trends — sightings without effort denominators (how many divers, how many hours) can’t support trend claims, so we don’t make them.
- Disease prevalence (e.g. Stony Coral Tissue Loss Disease outside well monitored jurisdictions).
- Crown of thorns starfishoutbreaks outside the GBR — AIMS publishes COTS for Australia; elsewhere it’s anecdotal.
Sources
Every quantitative claim on the site links back to one of these. Full list from src/data/sources.json.
- NOAA Coral Reef WatchU.S. National Oceanic and Atmospheric AdministrationU.S. Government Work (public domain)
Satellite-derived SST, SST anomaly, Degree Heating Weeks, and bleaching alert levels at ~5 km resolution. Use for current thermal stress, not for observed coral cover.
- Allen Coral AtlasArizona State University Center for Global Discovery and Conservation ScienceCC BY 4.0
Global high-resolution reef habitat maps and near-real-time bleaching detection. Habitat extents are observed; bleaching alerts are model-derived.
- Global Coral Reef Monitoring NetworkGCRMN / ICRI
In-situ benthic survey aggregations. Use for observed coral cover and historical bleaching mortality, with survey method and year.
Great Barrier Reef coral cover, bleaching, and crown-of-thorns surveys. Authoritative for GBR site-level observed condition.
Diver-conducted fish and invertebrate transects with effort metadata. Provides effort denominators for sighting probabilities at survey sites.
Aggregated species occurrence records. Confirms presence and seasonality clustering, never per-dive probability without effort data.
Marine-focused occurrence records. Use alongside GBIF for marine species presence and seasonality.
Diver safety guidance, incident data, and medical references. Use for safety and limitations language in beginner/returning flows.
- PADIProfessional Association of Diving Instructors
Certification level definitions and training-standard references. Use for skill-level recommendations, not for ecological claims.
- IUCN Red List of Threatened SpeciesInternational Union for Conservation of NatureFree for non-commercial use under IUCN terms
Authoritative conservation status (LC/NT/VU/EN/CR/EX) and population trend assessments. Use for species rarity and conservation framing.
- iNaturalistCalifornia Academy of Sciences & National Geographic SocietyCC0 / CC BY / CC BY-NC (per record)
Photo- and date-verified species occurrence records from citizen scientists. Strong recency signal; combine with GBIF/OBIS for presence and seasonality.
- Reef CheckReef Check Foundation
Global volunteer reef-monitoring program with standardised benthic and fish protocols. Use for observed reef condition where local surveys exist.
- Manta Trust IDtheManta DatabaseManta Trust
Photo-ID database of individual reef and oceanic mantas worldwide. Confirms aggregation site fidelity and seasonality.
Open photo-ID platforms for individual sharks, whale sharks, and mantas. Documents return visits to specific dive sites.
- NOAA National Coral Reef Monitoring ProgramNOAA Coral Reef Conservation ProgramU.S. Government Work (public domain)
Standardised biological, climate, and socioeconomic monitoring across US Caribbean and Pacific reefs. Use for observed reef condition.
- Great Barrier Reef Marine Park AuthorityAustralian Government
Authoritative manager for the Great Barrier Reef — zoning, reef-health outlook reports, and management plans. Use for GBR site-level travel and conservation guidance.
- Atlantic and Gulf Rapid Reef AssessmentAGRRA Program / Perry Institute for Marine Science
Standardised reef survey protocols and dataset for the wider Caribbean. Use for Caribbean coral cover and bleaching observations.
- International Coral Reef InitiativeICRI Secretariat
Intergovernmental partnership coordinating reef monitoring and protection. Use as a discovery layer for regional reef-status reports.
- SSIScuba Schools International
Alternative training-agency certification framework. Use alongside PADI for skill-level mapping, not for ecological claims.
- scubaSeason editorialscubaSeason.fun
scubaSeason editorial estimates compiled from operator websites, dive-travel agency listings, airfare aggregators, and direct destination research. Not live prices.
- DEMADiving Equipment and Marketing Association
Industry trade body — used only for travel-industry context, never for ecological or safety claims.
Physical Oceanography DAAC — canonical archive for SST, sea-surface salinity, sea level, ocean circulation, ocean winds. Hosts MODIS, GHRSST, SMAP, JASON/Sentinel-6, SWOT datasets.
- Copernicus Marine ServiceMercator Ocean International for the European UnionCopernicus data policy — free and open with attribution (CC BY equivalent)
Near-real-time and forecast SST, currents, chlorophyll, oxygen, pH for global and regional seas. Best single source for live anomaly cards on location pages.
ERDDAP-served satellite oceanography — SST, sea-level anomaly, chlorophyll-a, ocean heat content, sea-surface salinity, ocean winds. Programmatic per-coordinate access.
- NASA Ocean Color (OB.DAAC)NASA Goddard Space Flight Center / Ocean Biology Processing GroupU.S. Government Work (public domain)
Chlorophyll-a, water clarity, primary productivity from MODIS, VIIRS, OLCI, PACE. Use for site-level water-clarity context and productivity claims.
Global array of 4,000+ profiling floats measuring temperature, salinity, and biogeochemistry to 2 km depth. Use for ocean-interior temperature trend claims.
Real-time and historical in-situ wave, wind, water-temp, salinity, and atmospheric data from anchored buoys. Use for site-adjacent conditions where a buoy exists.
- OBIS-SEAMAPDuke University Marine Geospatial Ecology Lab / OBISCC BY (per-dataset; honor individual licenses)
Marine megafauna occurrence database — cetaceans, sea turtles, seabirds, sharks. Use alongside GBIF/OBIS for high-quality megafauna sighting records.
- HappywhaleHappywhale (Allied Whale / College of the Atlantic partnership)Free for research/non-commercial; commercial use requires permission
Photo-ID database for humpback, orca, sperm, blue, fin, and gray whales. Tracks individual animals across years — supports return-rate and seasonality claims.
- REEF Volunteer Fish SurveyReef Environmental Education FoundationPublic data with attribution; commercial use requires permission
275,000+ diver-conducted fish surveys with standardized methodology across the Americas, Caribbean, and Pacific. Use for diver-confirmed species presence claims with effort data.
Volunteer coral colour-chart survey program with 15+ years of bleaching observations from 100+ countries. Supports observed-bleaching claims at lower-monitoring sites.
- Ocean Tracking NetworkDalhousie University / OTNOpen data with attribution; per-dataset restrictions may apply
Global acoustic telemetry network tracking fish, sharks, turtles, and marine mammals. Use for migratory-corridor and residence-time claims for tagged species.
Australian oceanographic and biological observation data — moorings, gliders, animal tagging, satellite. Authoritative for Australian and Indo-Pacific waters.
Authoritative taxonomic backbone for marine species names. Use when normalizing common-name → scientific-name and for conservation-status lookups.
Comprehensive fish species reference — biology, distribution, ecology, conservation. Use for species-specific depth ranges, diet, behaviour claims.
Australian biodiversity aggregator with 130M+ occurrence records. Use for Great Barrier Reef and Coral Sea species claims.
- Protected Planet (WDPA)UNEP-WCMC + IUCNCustom — citation required; shapefile redistribution restricted; derived statistics with attribution fine
Canonical global database of marine and terrestrial protected areas. Use to state whether a dive site sits inside an MPA / no-take zone.
Protection-quality layer over WDPA — distinguishes paper-park MPAs from genuinely enforced no-take zones. Use to qualify MPA claims.
- Global Fishing WatchGlobal Fishing Watch (Oceana + SkyTruth + Google)CC BY-SA 4.0; API requires registration
AIS-derived fishing-effort data globally at 0.1° resolution. Use to indicate fishing pressure near dive sites and to support 'sits inside / outside fishing zone' claims.
Annual global mangrove extent and change layers since 1996 from satellite + ground truth. Use for mangrove-adjacent reef claims and habitat-decline context.
- Green FinsUNEP + Reef-World Foundation
UN-endorsed directory and standards for sustainable dive operators. Use to flag verified-responsible operators in trip recommendations.
Comprehensive global reef-threat assessment combining local and global pressures. Use for regional risk framing alongside in-situ surveys.
Annual composite index of ocean health by EEZ covering 10 goals (food provision, carbon storage, biodiversity, etc.). Use for country-level ocean-health context.
Authoritative US tide predictions, water levels, currents, and meteorological observations. REST API, no auth. Use for tide-window claims and current-strength context at US-territorial sites.
International Best Track Archive — every named tropical cyclone since 1842. Use for historical hurricane / typhoon / cyclone impact context at affected dive locations.
Global numerical-weather-prediction outputs at 0.25° resolution. Use for forward-looking wind, wave, and water-temp conditions cards.
- ERA5 reanalysis (Copernicus CDS)ECMWF / Copernicus Climate Change ServiceCopernicus data policy — free and open with attribution
Hourly atmospheric and oceanographic reanalysis from 1940 to present. Use for climatological 'typical conditions in October at this location' claims.
- HYCOM ocean modelHYCOM Consortium (US Navy + NOAA + academic)U.S. Government Work (public release, Distribution A)
Global hybrid-coordinate ocean circulation model. Use for currents, temperature/salinity profiles, and ocean-state forecasts at sub-coastal resolution.
- NCEI Marine MicroplasticsNOAA National Centers for Environmental InformationU.S. Government Work (public domain)
Global database of microplastic concentrations in seawater, sediment, and biota. Use for 'how plasticky is this water' framing at coastal locations.
Environmental Response Management Application and incident timeline of US oil spills + chemical releases. Use for active-incident context near US dive sites.
European seawater chemistry — nutrients, contaminants, microplastics, oxygen. Use for water-quality framing at Mediterranean / North Atlantic / Baltic sites.
Harmful algal bloom forecasts and bulletins for US waters. Use for active-bloom warnings near US dive locations.
- HAEDAT — Harmful Algae Event DatabaseIOC-UNESCO Intergovernmental Panel on Harmful Algal BloomsFree use with attribution
Global registry of HAB events with toxin, species, and impact records since 1985. Use for historical-HAB context at any coastal site.
- GOA-ON — Global Ocean Acidification Observing NetworkGOA-ON Secretariat + IOC-UNESCOOpen with attribution; per-dataset
Global pH and carbonate-chemistry observations from moorings + cruises. Use for ocean-acidification claims at the reef-health layer.
- NOAA Mussel WatchNOAA National Centers for Coastal Ocean ScienceU.S. Government Work (public domain)
Longest-running US coastal contaminant monitoring — heavy metals, PCBs, PAHs in shellfish tissue back to 1986. Use for historical-contamination context.
Global ocean-floor depth grid at 15-arcsecond resolution. Use for depth-context claims at any dive site, especially walls, dropoffs, and pinnacles.
Authoritative database of Holocene volcanoes worldwide with eruption history. Use for volcanic-origin context at island and seamount sites (Galápagos, Hawaii, Indonesia, Solomons).
- Naval History and Heritage Command (DANFS)US Naval History and Heritage CommandU.S. Government Work (public domain)
Dictionary of American Naval Fighting Ships — authoritative service histories for US Navy wrecks. Use for wreck dive pages (USS Liberty, SS President Coolidge, Chuuk fleet, Bikini Atoll).
Global earthquake catalog with magnitude, depth, location. REST API. Use for seismic-impact context at sites near active fault zones (Indonesia, Japan, Philippines, Aegean).
Electronic Navigational Charts including wreck and obstruction overlays. Replaces the retired AWOIS database. Use for wreck-position and obstruction lookups in US waters.
- NOAA Maritime Heritage ProgramNOAA Office of National Marine SanctuariesU.S. Government Work (public domain)
Underwater cultural heritage protection within US National Marine Sanctuaries — wreck preservation status, archaeology, regulations. Use for wreck-protection framing.
Open nautical chart tiles with crowd-sourced harbours, lights, wrecks, and buoys. Use only as a cross-reference layer, not as authoritative wreck-identity data.
- IPCC Special Report on the Ocean and Cryosphere (SROCC)Intergovernmental Panel on Climate ChangeFree with attribution
The peer-reviewed reference for climate impacts on the ocean. Use to frame long-horizon outlook claims with appropriate confidence levels.
Methodology
How each claim is constructed and the limitations we’ll own up to. Full list from src/data/methodologies.json.
- dive-conditions-forecasttravel-recommendationconfidence: medium
Conditions claims (wave height, wind, swell, current, water temp, tide windows) are sourced from peer-reviewed forecast and reanalysis models — they are statistically calibrated but not site-specific to the metre. Tropical-cyclone history is from IBTrACS. None of this replaces a local operator's morning briefing. We use these for climatological 'what to expect in this month' framing, not day-of dive go/no-go calls.
Sources: noaa-co-ops, ibtracs, ecmwf-open, era5, hycom, copernicus-marine, noaa-coastwatch, noaa-ndbc
- water-quality-pollutionreef-healthconfidence: medium
Pollution and water-quality claims are sourced from governmental monitoring networks and peer-reviewed registries — coverage is excellent in the US, EU, and Australia and patchier elsewhere. Microplastic concentrations vary enormously by time, season, and depth — published values are sparse spatial averages. Harmful algal bloom forecasts are short-term (days to weeks) and species-specific. Always confirm current advisories with the local operator before relying on this layer for site selection.
Sources: ncei-microplastics, noaa-erma, emodnet-chemistry, noaa-hab-forecast, haedat, goa-on, noaa-mussel-watch, global-mangrove-watch
- wreck-history-bathymetrytravel-recommendationconfidence: high
Bathymetry comes from GEBCO at 15-arcsecond global resolution — good for depth context but not survey-grade for navigation. Wreck history is taken from naval / governmental archives (DANFS, ENC Direct, NOAA Maritime Heritage) which are authoritative for cited vessels but do not cover every sport-dive wreck worldwide. Volcanic and seismic context (Smithsonian GVP, USGS) is event-level — use for 'this site sits near an active fault / volcano' framing, not for risk assessment.
Sources: gebco, smithsonian-gvp, usn-nhhc, usgs-earthquake, noaa-enc-direct, noaa-maritime-heritage, openseamap
- human-pressure-mpa-contexttravel-recommendationconfidence: medium
MPA boundaries are taken from Protected Planet (WDPA); not every MPA is genuinely enforced — Marine Protection Atlas adds a protection-quality layer to distinguish paper-park designations from no-take protection. Fishing-pressure proxies come from Global Fishing Watch AIS data, which captures industrial vessels but misses small-scale and illegal fishing. We use these layers for context — not to certify that a specific site is well-managed or fish-stocked. Always confirm permits and rules with the local operator before booking.
Sources: wdpa, mpatlas, global-fishing-watch, global-mangrove-watch, green-fins, wri-reefs-at-risk, ocean-health-index
- trip-cost-editorial-2026travel-recommendationconfidence: medium
Trip-cost estimates are editorial ranges, not live prices. Flight ranges reflect typical round-trip economy fares from each regional hub during the location's dive season; off-season or last-minute fares often fall outside. Lodging tiers are per-night ranges for double-occupancy mid-week stays — peak holiday weeks (Easter, Christmas/New Year, Chinese New Year) commonly run 20–50% higher. Dive-day prices assume a 2-boat-dive package with tanks/weights/guide included and exclude private guide, nitrox, and equipment rental. We do not claim accuracy beyond ±15%; book operators directly to confirm.
Sources: editorial-curation, dema, padi, ssi
- reef-health-aims-noaareef-healthconfidence: high
Observed coral cover, bleaching, and mortality come from named in-situ surveys with a stated date and method — they describe one snapshot of one reef and do not extrapolate to neighbouring sites. Current thermal stress is satellite-derived from NOAA Coral Reef Watch at ~5 km resolution; it indicates risk, not observed coral damage. We deliberately separate observed condition, current thermal stress, and projection — and we never publish a projection without a documented model and uncertainty.
Sources: aims-ltmp, gcrmn, agrra, ncrmp, reef-check, noaa-crw, noaa-coastwatch, allen-coral-atlas, gbrmpa, icri, reef-life-survey, nasa-podaac, copernicus-marine, nasa-ocean-color, argo, coralwatch, imos-aodn, wri-reefs-at-risk, ocean-health-index, ipcc-srocc, goa-on, haedat, ncei-microplastics
- sighting-occurrence-clusterspecies-presenceconfidence: medium
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: gbif, obis, obis-seamap, inaturalist, iucn-red-list, worms, fishbase, atlas-living-australia, reef-org
- encounter-sardine-run-seasonalityseasonalityconfidence: medium
Best months are derived from clustering of occurrence records and operator-reported seasons. No per-trip probability is published — the Sardine Run varies year to year with current and water temperature.
Sources: gbif, obis
- encounter-great-white-cage-presencespecies-presenceconfidence: medium
Regional populations have shifted; operator availability changes annually. We do not publish per-trip probability.
Sources: gbif, dan, iucn-red-list, wildbook
- encounter-hammerhead-schools-presencespecies-presenceconfidence: medium
Schooling behavior is operator-reported. Aggregation density varies with current, lunar phase, and temperature.
Sources: gbif, obis, iucn-red-list
- encounter-whale-shark-seasonalityseasonalityconfidence: high
Best months are derived from occurrence-record clustering and well-documented regional aggregations. Per-trip probability is not published.
Sources: gbif, obis, obis-seamap, wildbook, ocean-tracking-network, iucn-red-list
- encounter-manta-cleaning-presencespecies-presenceconfidence: high
Cleaning stations are site-specific; visit frequency varies with current and time of day.
Sources: gbif, obis, obis-seamap, manta-trust, iucn-red-list
- encounter-thresher-cleaning-presencespecies-presenceconfidence: high
Monad Shoal threshers are reliably present year-round but encounters are pre-dawn and weather-dependent. No per-dive probability.
Sources: gbif, obis, iucn-red-list
- encounter-mobula-aggregation-presencespecies-presenceconfidence: medium
Aggregation timing shifts with water temperature and prey. Encounter is occurrence-clustered, not survey-measured.
Sources: gbif, obis, manta-trust, iucn-red-list
- encounter-blackwater-conducttravel-recommendationconfidence: high
Subject diversity is highly variable. We do not list per-species probabilities for blackwater dives.
Sources: obis, padi
- encounter-coral-spawning-seasonalityseasonalityconfidence: medium
Exact spawning night varies by reef and year. Predictions are operator-tracked and affected by ocean temperature anomalies.
Sources: aims-ltmp, gcrmn, gbrmpa, icri
- encounter-mandarin-spawning-presencespecies-presenceconfidence: high
Daily ascent is consistent at established rubble sites but very brief; not a guarantee on any single dive.
Sources: gbif, obis, inaturalist
- encounter-giant-cuttlefish-seasonalityseasonalityconfidence: high
Aggregation numbers fluctuate; the Spencer Gulf population crashed in the 2010s and has only partially recovered.
Sources: gbif, obis, inaturalist
Questions about a specific claim? FAQ / hi@scubaseason.fun.