Reef Explorers
Stepped rock terraces of the Yonaguni Monument
Advanced≤30 m

Yonaguni Monument (Underwater Ruins, Iseki Point)

Dive site in Okinawa & Yonaguni, Japan

Giant terraced rock formations, natural or man-made depending on who you ask, with schooling hammerheads in winter.

Usual dive
17 m
Deepest point
25 m
Level
Advanced
Best months
Dec–May
Entry
By boat
Current
Strong

Photo: Melkov, CC0, via Wikimedia Commons

The story

In 1986, while looking for sharks, Kihachiro Aratake of the Yonaguni-Cho Tourism Association noticed seabed formations resembling architectural structures. Geologist Masaaki Kimura claims they are man-made; Robert M. Schoch thinks they are most likely natural.

Source: en.wikipedia.org

The dive

A rock formations dive from a boat.

Who it's for

Advanced≤30 mSource: bluejapan.org

Recommended minimum: Advanced (PADI Advanced Open Water, N2).

  • CurrentCurrent can be strong; you need good air management and buoyancy.
  • Strong current: dive with a local guide and carry a surface marker buoy.

Conditions

Dive type
Rock formations
Environment
Open water
Water
Sea water

Why divers come

  • Mystery structure
  • Geology

Best time to dive

  • Best
  • Good
  • Possible
  • Closed
  • Not documented yet

Best months: Dec–May.

Source: en.marinediving.com

Where is Okinawa & Yonaguni?

View on OpenStreetMapLocation: Okinawa Island (Wikipedia)Map: Natural Earth

The point shows the Okinawa & Yonaguni area, not the exact dive site.

About this page

Values marked “Estimated” come from our original catalogue and are being checked against published sources one by one. Sourced values link to where they come from. Conditions change with the season, the weather and the tide: confirm with a local dive centre before you dive.

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