A New Depth of Partnership: ROK Navy Opens Its Most Advanced Submarine to a Canadian Submariner 

In a milestone moment for undersea cooperation, the Republic of Korea Navy (ROKN) welcomed a Royal Canadian Navy (RCN) submariner aboard one of its most advanced submarines—the 3,000-ton SS-III ROKS Ahnmu—during Exercise Silent Shark 2025. Conducted from December 5 to 10, the at-sea training marked a rare opportunity: for the first time, a foreign submariner trained aboard a Dosan Ahn Chang Ho-class submarine, Korea’s flagship next-generation fleet.

The embark was more than symbolic. It was a hands-on exchange designed to deepen the growing operational relationship between the ROKN and RCN, particularly as Canada advances the Canadian Patrol Submarine Project (CPSP). By opening ROKS Ahnmu to Canadian participation, the ROK Navy demonstrated both confidence in the platform and its commitment to broadening international collaboration in undersea operations.

“The first-ever embark training with a RCN submariner aboard the Dosan Ahn Chang Ho-class submarine ROKS Ahnmu during this exercise stands as a symbol of close engagement and mutual cooperation between our navies,” said Captain Geonyoung Ahn, the commanding officer of ROKS Ahnmu. “This training and experience aboard the ROK submarine will serve as a great opportunity to once again verify the excellence of the ROK Navy submarines, and moreover, as a catalyst for the ROK Navy’s contributions to Korean maritime defense exports.”

Strengthening Submarine Bonds Through Real-World Training

The RCN submariner selected for this unprecedented embark was Chief Petty Officer First Class (CPO1) Etienne Langlois, a 27-year veteran sonar technician and instructor with extensive experience aboard Victoria-class submarines. From day one of the Silent Shark exercise, he stepped directly into the rhythm of Ahnmu’s crew.

Throughout the training period, the submarine executed an ASW passing exercise, free-play engagements, and combined ASW operations—all of which offered CPO1 Langlois unmatched visibility into tactical procedures, crew coordination, and operator workflows. These were not demonstrations staged for visitors; they were active, mission-focused evolutions, allowing him to experience the boat exactly as its crew does.

The result was a realistic immersion into how the SS-III class performs under pressure. For Langlois, it was also an opportunity to compare approaches: how Canada and Korea each train, fight, and adapt below the surface at a time when threats in the Indo-Pacific and North Pacific are increasing in complexity.

“The embark program aboard ROKS Ahnmu allowed me to build a strong camaraderie with ROK submariners and also to see firsthand the advanced level of technology on the submarine that the ROK domestically built,” said CPO1 Langlois. “I look forward to achieving mutual growth through continued engagement between our navies.”

A Rare Look Inside the Dosan Ahn Chang Ho-Class

While ROKN submariners have frequently embarked foreign partners aboard other classes—including the 1,200-ton Jang Bo Go-class (SS-I) and 1,800-ton Son Won Il-class (SS-II)—the opening of the SS-III to a foreign submariner represents an unprecedented level of transparency and partnership.

During the exercise, ROKS Ahnmu’s crew introduced CPO1 Langlois to systems, capabilities, and operator tools that differ significantly from those found on RCN platforms. Their goal: offer not just a tour, but a true operator-level understanding of what makes the class exceptional.

From its advanced combat systems to its acoustic management technologies, the Dosan Ahn Chang Ho-class reflects the ROK’s growing position as a leading submarine designer and builder—an important consideration as Canada evaluates its future undersea fleet.

Momentum for a Growing Partnership

The ROK Navy notes that the embark program was designed to maintain forward momentum in submarine cooperation while supporting Canada’s CPSP. It is also part of a broader push by the ROK to expand personnel exchanges, training opportunities, and technology partnerships with like-minded Indo-Pacific and North American navies.

Looking ahead, the ROK Navy underscores that it will continue advancing a Total Solution approach to maritime defence exports—including submarines and frigates—reflecting its ambition to contribute more deeply to global naval security.

For both nations, the embark aboard ROKS Ahnmu signals a meaningful step toward stronger interoperability, shared learning, and deeper defence collaboration beneath the waves.