Fathom Deep Ocean Institute · est 1994
Ninety-five per cent of the ocean floor has never been seen.
We run one ship and one vehicle rated to seven thousand metres, out of Kochi. Every dive log, every sensor cast and every core is published as recorded, including the dives that found nothing worth writing up.
- Deepest dive
- 6,740 m
- Dives logged
- 3
- Papers
- 4
- Last at sea
- 2026-02-19
The column
Five zones, and we work in three of them.
The ocean is on average 3,700 metres deep, and the deepest trench is nearly three times that. Sunlight stops at 200. Everything below that line is the largest habitat on the planet and the least visited part of it.
- 0 to 200
- SunlightEverything that photosynthesises lives here.
- 200 to 1,000
- TwilightEnough light to hunt by, not enough to grow.
- 1,000 to 4,000
- MidnightNo sunlight at all. Most light here is made by animals.
- 4,000 to 6,000
- AbyssalNear freezing, and under four hundred atmospheres.
- 6,000 to 11,000
- HadalTrenches only. Less mapped than the surface of Mars.
Twilight200 m
Midnight1,000 m
Abyssal4,000 m
Hadal6,000 m
6,740 mFD-207
Sunlight, 0 to 200 m, is the band at the top too thin to letter.
Dive log
All dives- FD-214Carlsberg RidgeNorthwest Indian OceanA hydrothermal field on a slow-spreading ridge, mapped at metre resolution for the first time.3,480 m2026-02-19
- FD-207Sunda Trench, north wallEastern Indian OceanFirst hadal-zone dive from this vessel. Sediment cores, and more plastic than anybody wanted to report.6,740 m2025-11-04
- FD-198Ninety East RidgeCentral Indian OceanA seamount summit survey, and an octopus nursery nobody expected at this latitude.2,110 m2025-06-27