The record What this system is, where it comes from, who operates it and which of Vigil’s modules it is relevant to — with the evidence each of those rests on.
Record
Conflict relevance
This is the catalogue's single record for this system. It is relevant to the module below; each module's Force Atlas shows how it is used there.
Operators
Taiwan (Republic of China): Prototype in sea trials; not an in-service capability
Battlefield role
Intended for sea denial in the waters and approaches around Taiwan.
Strengths
Submarines are among the hardest platforms to find and neutralise, and building them domestically after decades of being unable to buy them is a substantial industrial achievement with real deterrent signalling value.
Limitations
The programme is slow, expensive and unproven: the prototype has been conducting sea trials rather than entering service, and schedules have moved repeatedly. Critics within the asymmetric-defence school argue the cost would buy far more denial capability in missiles, mines and small craft. Vigil records the trials as reported milestones and makes no claim about capability, timeline or fleet size.
Campaign relevance
Derived: a participant organisation in these campaigns carries a typed equipment association with this system. That is not the same as documented use of the system in the campaign itself.
- Sustained pressure below the threshold Intensifying since 2020
via ROC Navy (Prospective, moderate confidence)
- Coercive maritime interdiction — quarantine to blockade Assessed contingency
via ROC Navy (Prospective, moderate confidence)
Visual identification
A conventional diesel-electric submarine with an X-form stern rudder arrangement — four angled control surfaces rather than the cruciform layout of the older boats Taiwan operates — and a slender sail set well forward. The X-stern is the distinguishing feature and is visible only out of the water.
Documented conflict use
Launched in September 2023 and engaged in harbour and sea trials since, with delivery repeatedly rescheduled; the boat has not entered operational service. It left on its 21st sea trial, the 15th with submerged testing, on 21 September 2026, having missed the November 2025 delivery deadline its builder attributed to testing delays. Follow-on hulls are funded in Taiwan's special defence budgets and are the subject of continuing legislative argument. Vigil records trials and budget decisions as reported milestones and makes no claim about capability, timeline or eventual fleet size — this is the record in the Taiwanese catalogue where the gap between programme announcement and delivered capability is widest, and the confidence grade says so.
Branch & service operators
- ROC Navy Prospective
Reported, prospective & historical formation associations
- ROC Navy Fleet Command Prospective · moderate confidence · Announced
Programme in trials; not an in-service capability claim.
Assessed as of — 2026-09 Last reviewed — 2026-09-27