OCEAN · OCEANS & SEAS · PACIFIC OCEAN
Seto Naikai or Inland Sea
The Seto Naikai or Inland Sea is a sea of the Pacific Ocean, covering 18,131 km² — the #93 largest of the world's 101 named ocean and sea areas. Here's how it ranks, what borders it, and the live conditions at its centre right now.
Boundaries & area: Marine Regions (VLIZ), IHO Sea Areas v3 — from the IHO “Limits of Oceans & Seas” (S-23). MRGID 4306.
Live from Open-Meteo Marine at 34.1°, 133.0° (the sea's representative centre). A near-real-time model estimate.
How deep is the Seto Naikai or Inland Sea?
The IHO sea-area dataset that draws this map records each sea's name, boundary and surface area — not its depth, which varies enormously from the shallow shelf at its edges to its deepest trench. Rather than quote a single misleading number, we measure the water column directly: the live ocean currents trace its motion, and the deep-ocean layers (Argo floats and the descend-here column, coming to the Ocean canvas) read real temperature and depth as you go down.
SEE IT ON THE MAP
See the Seto Naikai or Inland Sea coloured on the live oceans-&-seas map.