Horizon Deep at a glance
- 8,454 mdeep in the grid
- Deeptype of feature
- 25.00° S, 175.00° Wlisted point
- Tonganearest country, about 319 km
- 10,817 mWikidata's own depth
- 5 of 24deepest of the deeps in our list
Horizon Deep is a deep. In the GEBCO grid it reaches 8,454 m below sea level. That figure is the deepest cell in the grid within 20 km of its listed point. The nearest country in our list is Tonga, about 319 km from its listed point.
Open the main map at the deepest cell and tap anywhere to read the depth.
How deep is the Horizon Deep?
The grid figure is 8,454 m. We measured it as the deepest cell in the grid within 20 km of its listed point. The cell is at 24.92° S, 175.13° W. The GEBCO_2026 grid has a value every 15 arc-seconds, about 460 m at the equator, so a very narrow feature can be a little deeper or shallower in reality than any grid cell shows.
Wikidata gives 10,817 m, which is 2,363 m deeper than the grid figure of 8,454 m. Published depths for the same feature often differ like this: they can come from one ship's sounding of one spot rather than a gridded model, or refer to a different part of a long feature. We show both, and use the grid figure in our headline numbers because every depth on this site then comes from one source.
Among the 24 deeps in our list it ranks 5th by depth. The list is the named features on Wikidata with a position at sea, so it is not every deep in the world.
About deeps
A deep is the deepest part of a trench or basin: a small area, often only a few kilometres across, that gets its own name.
This site lists 24 deeps, 13 of them with their own indexed page. See all undersea features.
Nearby undersea features
- Tonga-Kermadec Ridge undersea ridge, about 0 km away
- Osbourn Seamount seamount or guyot, about 112 km away
- Monowai Seamount seamount or guyot, about 241 km away
- Gamble Seamount seamount or guyot, about 345 km away
- Unnamed volcano seamount or guyot, about 408 km away
- Unnamed submarine volcano seamount or guyot, about 435 km away
Distances are between listed points. A long feature such as a trench or ridge has a single listed point on Wikidata.
The deepest deeps in our list
- Vityas Deep 1 10,931 m
- Challenger Deep 10,927 m
- Sirena Deep 10,751 m
- Scholl Deep 10,040 m
- Milwaukee Deep 8,405 m
- Meteor Deep 8,041 m
Frequently asked questions
How deep is the Horizon Deep?
In the GEBCO grid the figure is 8,454 m. That is the deepest cell in the grid within 20 km of its listed point. Wikidata gives 10,817 m, which is 2,363 m deeper than the grid figure of 8,454 m. Published depths for the same feature often differ like this: they can come from one ship's sounding of one spot rather than a gridded model, or refer to a different part of a long feature. We show both, and use the grid figure in our headline numbers because every depth on this site then comes from one source.
Where is the Horizon Deep?
Its listed point is 25.00° S, 175.00° W, about 319 km from Tonga. The grid's deepest cell for it is at 24.92° S, 175.13° W.
Data: depth from the GEBCO_2026 grid. Name and position from Wikidata Q1628178 (CC0). See data sources and licences. The GEBCO Grid should NOT be used for navigation or for any other purpose involving safety at sea.
All undersea features · All oceans and seas · Drain the oceans