About Fin
Fin is an encyclopedia of the world's dive and snorkel sites: a database of 35,000+ sites compiled from more than 20 published sources, checked against scientific datasets, and made sharper by every dive logged on it.
Where the data comes from
Every number on a Fin page traces back to a source. The main ones:
OBIS (Ocean Biodiversity Information System)
Species occurrence records contributed by research institutions worldwide. Fin matches these records to dive sites to show which species are found where, validated per site before publication.
WoRMS (World Register of Marine Species)
The authoritative register of marine species names, maintained by taxonomists. Every scientific name on Fin is validated against WoRMS, so synonyms and outdated names resolve to the current accepted species.
NOAA temperature datasets
Monthly water temperatures come from the NOAA Optimum Interpolation SST dataset (OISST). Air temperatures come from the GHCN-CAMS observational grid. These are measured values, not estimates.
Published dive site sources
Names, coordinates, depths and access details compiled from more than 20 published sources, then cross-checked, deduplicated and corrected. Provenance is tracked per field.
Divers
Logged dives, species sightings, reviews and corrections from people who have been in the water at these sites. This is the layer no published source can provide: what divers actually saw, and when.
A complete site record covers more than 50 fields: depth range, entry type, currents, hazards, monthly water and air temperatures, visibility, facilities, certifications and access. Across all sources, Fin holds more than 900,000 species-to-site links covering 1,100+ species.
Every logged dive makes the data better
Each dive logged on Fin records what a diver actually saw: the species, the month, the conditions. One log is an anecdote. Thousands of logs at a site show which species turn up, how often, and in which months.
That pattern is what makes the encyclopedia useful. It separates common sightings from rare ones, and over time it traces seasonal movements: when the mantas arrive, when the whale sharks pass through, when the nudibranchs are out. If there is a species you want to see, the logs show where and when divers actually see it.
So every dive you log sharpens the picture for the next diver. The richer the log book, the better the map.
How we use AI
AI does two jobs behind Fin. It researches site details by gathering and cross-checking published sources, with every field tracked back to where it came from. It also drafts the written descriptions and FAQs from that researched data, which then pass automated quality checks before publication.
Water temperatures and species records work differently: they come straight from the NOAA and OBIS observational datasets above, not from AI. And our rule for everything else is simple: when a fact can't be verified, we leave it out. We would rather show a gap than a guess.
Spotted something wrong?
Every site page has a Suggest Edit option. Corrections are reviewed and applied to the live database, and hazard reports confirmed by two independent divers are applied automatically.