NAVAREA XI - 25-0412

Issued: 2 Sept 2025, 09:00Last modified: 1 Nov 2026, 03:02

analysisNotable

Active

Volcanic eruption continuing at Io To (Nanpo Shoto) - exercise caution

A volcanic eruption is reported continuing at Io To in the Nanpo Shoto (North Pacific). Mariners are requested to exercise caution in the area. No positions, times or safety distances are provided. This message cancels warning 0539/24.

Exercise caution when transiting the area and maintain a proper lookout; avoid the vicinity of the erupting island.

Background

Io To (Ioto, also known as Iwo Jima historically) is a volcanic island in the Nanpo Shoto (Ogasawara/Bonin) chain south of the main Japanese islands and is known for volcanic activity. Eruptions can produce ash plumes and floating pumice that pose hazards to navigation, engines and visibility. Warnings for this area are routinely promulgated by Japanese NAVAREA authorities when eruptive activity is ongoing. Mariners should expect the hazard to be local to the island but may be affected by drifting volcanic material depending on winds and currents.

General background from general knowledge, not from the official warning. It can be wrong; the warning text is authoritative.

Type: Navigational hazard · severity high
Feed: Wrecks, obstructions and drifting objectsAll warnings of this kind on the map (contributors), or as an API feed: /api/v2/feeds/hazards/
Location: North Pacific, Nanpo Shoto, Io To
Hazards: volcanic eruption, ash and volcanic debris, possible pumice rafts or floating volcanic material
Cancels: 0539/24

Generated automatically from the warning text on 08 Oct 2026, 13:39 UTC. It can be wrong: the original warning below is the authoritative text.

Message content

NORTH PACIFIC, NANPO SHOTO. IO TO. VOLCANIC ERUPTION CONTINUE. VESSELS REQUESTED TO BE CAUTION ADVISED. CANCEL 0539/24. NAVAREA XI

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