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Tsurugi-class patrol vessel

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General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionMar 5, 2026
Entity authorityQ4310132 ↗
Source-derived summary

The Tsurugi class (Japanese: つるぎ型巡視船) is a class of small patrol vessel of the Japan Coast Guard (JCG). The development of this class was one of the earliest attempts of the JCG to deal with spy boats from North Korea. In March 1999, the JCG tried to intercept vessels of unknown nationality suspected to be North Korean, but the unknown vessels were too fast, and the Japan Maritime Self-Defense Force had to be called to intercept the unknown vessels. As a consequence of this failure, JCG realized their need for high speed interceptors.

The Tsurugi class is referred to as High-speed, special-purpose patrol vessels (高速特殊警備船, Koutoku-sen). Planned as the top-tier of JCG intercept spy boats, this class features very high speed and accurate firepower. Its weaponry includes a JM61 20 mm Gatling gun, and a Remote Firing System consisting of a remote weapon system with a laser-optical fire-control system.

In the Battle of Amami-Ōshima, the combination of the 20 mm gun with the RFS proved its worth, but it became clear that its effective range was insufficient against weapons on board the North Korean spy boats such as 9K38 Igla MANPADS and B-10 recoilless rifle. In response, the JCG intends to organize mobile flotillas combining Tsurugi-class ships with vessels of the Hida and Aso classes, which have Bofors 40 mm L/70 autocannons.

Ships in the class

See also

List of Japan Coast Guard vessels and aircraft

References

Future reading

"Ships of Japan Coast Guard".

Editorial summary

“Tsurugi-class patrol vessel” enters the record as open-knowledge reference entry. Crown Archives preserves that source wording while asking what Tsurugi-class, patrol and vessel can confirm, complicate or overturn.

Editorial reviewA concise reference frame for defining the subject, testing terminology and identifying the institution closest to the evidence. The current lead gives the account dated anchors—1999—that can be checked directly. The selected authority fields contribute no independent date. Its strongest next move is a source search built around Tsurugi-class, patrol and vessel.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Mar 5, 2026. The linked authority identifier is Q4310132. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1999.

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This entry incorporates text from “Tsurugi-class patrol vessel” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.