Taiwan's submarine dream is becoming a reality

Taiwan’s century-old submarine dream is coming true amid rising regional tensions.

The Republic of China’s (ROC) pursuit of submarine capabilities dates back more than a century. In 1913, under the Beiyang Government—a military-led regime that controlled much of northern China following the fall of the Qing Dynasty—the ROC Navy proposed a seven-year shipbuilding program to then-President Yuan Shikai (袁世凱), aiming to build 18,000 tons of submarines by 1920 to counter the growing strength of the Imperial Japanese Navy.

However, lacking the necessary technical expertise and national capacity, the plan was never realized.

The next attempt came in 1937, when the Nationalist government placed an order with Germany for five submarines—one Type VII and four Type UIIB. Although personnel training had begun, the outbreak of World War II led the Kriegsmarine to requisition the vessels and refund the payment, abruptly ending the initiative.

A third effort followed the ROC’s relocation to Taiwan in 1950, when the Ministry of National Defense (MND) proposed building miniature submarines. In 1952, Admiral Ma Chi-chuang submitted a development report to the U.S. Military Assistance Advisory Group. However, there is no evidence that these mini-submarines were ever commissioned into formal service.

In 1961, Taiwan initiated the “Sea Shark Project,” acquiring two-man submersibles from Italy for special operations forces. These crafts laid the foundation for Taiwan’s first special warfare undersea unit—the “Hai Chang Unit”—which later inspired the name of the indigenous submarine initiative, the “Hai Chang Program,” as a tribute to these early efforts.

The campaign to develop undersea capabilities continued. In 1963, the MND launched the “Wu Chang Project,” commissioning two Italian-designed mini-submarines—Hai Jiao and Hai Long—for local assembly in Taiwan. These marked the first officially documented submarines built in Taiwan.

By 1969, Taiwan formally requested to procure 10–12 submarines from the United States. Washington rejected the request, citing the offensive nature of submarines. Nonetheless, in 1971, the U.S. transferred two upgraded Tench-class GUPPY II submarines to Taiwan, which entered service as ROCS Hai Shih and ROCS Hai Bao. Unverified reports suggest the U.S. decision was partly influenced by sightings of earlier indigenous prototypes being tested in the Tamsui River.

In 1978, Taiwan revisited the idea of building its own submarines but ultimately shelved the plan after concluding that technical limitations and international constraints made it unfeasible.

A year later, a financial crisis at Dutch shipbuilder Rijn-Schelde-Verolme (RSV) provided an opening. Taiwan sought to procure four Swordfish-class submarines, but due to pressure from Beijing, the Netherlands authorized the sale of only two, which were later commissioned as ROCS Hai Hu and ROCS Hai Lung. After this acquisition, Taiwan’s submarine program again entered a prolonged period of stagnation.


Revival of the Submarine Program

A renewed opportunity emerged in 2001 when U.S. President George W. Bush’s administration approved the sale of eight diesel-electric submarines to Taiwan. However, the U.S. no longer maintained a production line for conventional submarines, having transitioned entirely to nuclear-powered models. The success of the plan hinged on European cooperation—support that ultimately did not materialize, leaving the initiative deadlocked.

In parallel with faltering external procurement efforts, domestic momentum began to build. Kuomintang (KMT) Legislator Lin Yu-fang (林郁方) proposed legislation endorsing the Indigenous Defense Submarine (IDS) policy, providing the legal framework for Taiwan to pursue its own submarine construction program.

By 2014, then-Commander of the Republic of China Navy (ROCN), Admiral Chen Yeong-kang (陳永康), publicly called for Taiwan to stop waiting and begin building submarines domestically. He formed a planning team to study submarine architecture and procurement mechanisms.

According to Retired Rear Admiral Hsia Kuang-ya (夏光亞), Admiral Chen’s leadership not only launched the IDS initiative but also introduced a broader 12-project “National Shipbuilding Program,” which included new classes of amphibious transport docks, frigates, rescue vessels, mine-layers, marine survey ships, special operations platforms, and more.

These projects, gradually brought to fruition in recent years, are transforming Taiwan’s navy from a procurement-dependent force into a modernized, self-sustaining maritime power. Given the program’s long-term strategic significance, Admiral Chen deserves recognition as a pivotal architect in the ROCN’s modernization history.

The IDS program—named the “Hai Chang Program”—was formally launched in April 2014. Initial momentum was reinforced in September of that year when Admiral Chen convinced then-U.S. Chief of Naval Operations Admiral Jonathan Greenert to publicly acknowledge U.S.–Taiwan dialogue on indigenous submarines. This rare diplomatic gesture significantly eased political resistance to the initiative.

After the 2016 election of President Tsai Ing-wen, the program gained further institutional backing. The MND structured the IDS initiative into two phases: contract design and physical construction. Both were awarded to Taiwan’s state-owned shipbuilder, CSBC Corporation.

With no prior experience in modern submarine construction, Taiwan effectively started from zero. The country had to develop its own blueprints, secure specialized materials, and build entirely new shipyard facilities. By 2020, with the completion of critical infrastructure and systems testing, construction of the first prototype submarine officially began.

Challenges in Taiwan’s Submarine Sea Trails

In 2023, Taiwan unveiled its prototype, the ROCS Hai Kun, hull number SS-711. It entered port trials that year and is expected to begin sea trials by 2025.

With this milestone achieved, the MND has allocated NT$284.08 billion (approximately USD 9 billion) to construct seven follow-on submarines through 2038. The initial budget for 2025 was set at NT$2 billion.


Due to the long timeline and significant investment involved, opposition lawmakers have approached budget approval with caution. Since the Hai Kun submarine has yet to begin its Sea Acceptance Test (SAT), opposition legislators proposed freezing 50% of the follow-on budget until two conditions are met: the Hai Kun must successfully complete sea trials, and the Ministry of National Defense (MND) must submit a special report to the Legislative Yuan for formal approval.

Originally scheduled for April 2025, the SAT has been repeatedly delayed. Unconfirmed reports in May 2025 suggested a propulsion issue, though these claims remain unverified.

Lawmakers from across party lines have emphasized that safety must come first and have urged that sea trials only begin once all critical systems are fully ready.

Rear Admiral (ret.) Hsia Kuang-ya (夏光亞) noted that sea trials require extensive preparation, including testing the submarine’s ballast systems, propulsion, combat systems, air and life-support, and weapons platforms. He stressed that safety is non-negotiable. Taiwan’s limited suitable sea trial areas—many predictable and monitored by the People’s Liberation Army—add to operational risks, underscoring the need for caution.

The ROC Navy’s deliberate and methodical approach to the Indigenous Defense Submarine (IDS) program highlights its strategic importance—not just as a hardware purchase but as a symbol of national resilience and industrial independence.

Since relocating to Taiwan in 1949 after the Chinese Civil War, the Republic of China has relied heavily on its navy as the first line of defense against potential aggression from the People’s Liberation Army. As Beijing continues expanding its naval dominance, submarines—offering stealth, survivability, and strategic deterrence—have become essential to Taiwan’s defense.

Developing an indigenous submarine fleet represents not only a long-held strategic goal but also a cornerstone of Taiwan’s broader national defense plan. Today, Taiwan stands on the verge of fulfilling a century-old ambition—one that could reshape its role in Indo-Pacific maritime security for decades to come.