South Korea Showcases KSS-III Submarine to Canada Amid Naval Modernization Drive

Milivox analysis: South Korea is positioning its KSS-III diesel-electric attack submarine as a potential contender for Canada’s future submarine program. The move underscores Seoul’s growing ambitions in the global naval export market and aligns with Ottawa’s urgent need to replace its aging Victoria-class fleet.

Background

On November 18, 2025, Canadian Prime Minister Justin Trudeau visited the Hanwha Ocean shipyard in Geoje, South Korea. The high-profile visit included a tour of the KSS-III (also known as Dosan Ahn Changho-class) submarine production line—a clear signal of Seoul’s intent to pitch its most advanced conventional submarine for export. This engagement comes amid Canada’s ongoing efforts to identify a replacement for its four-decade-old Victoria-class submarines under the Canadian Patrol Submarine Project (CPSP).

The visit follows increased bilateral defense cooperation between South Korea and Canada and reflects Seoul’s broader strategy of leveraging its domestic defense industrial base for international arms sales. Hanwha Ocean (formerly Daewoo Shipbuilding & Marine Engineering) is one of South Korea’s premier naval shipbuilders and plays a central role in the Republic of Korea Navy’s (ROKN) indigenous submarine development program.

Technical Overview

The KSS-III is South Korea’s first fully indigenous diesel-electric attack submarine class and represents a significant leap from earlier German-designed Type 209/214 variants operated by the ROKN. The Block-I variant displaces approximately 3,700 tons submerged and measures around 83.5 meters in length—making it one of the largest conventional submarines currently on offer globally.

Key features include:

• Air-independent propulsion (AIP): Fuel-cell-based AIP extends submerged endurance significantly beyond traditional diesel-electric designs.
• Vertical Launch System (VLS): Six VLS cells capable of launching Hyunmoo-4-4 cruise missiles or other land-attack munitions—rare among SSKs.
• Sensors: Advanced sonar suite including flank arrays and low-frequency passive sonar; integrated combat system developed by LIG Nex1.
• Crew & Automation: Designed for ~50 personnel with high levels of automation reducing crew workload.
• Stealth Features: Anechoic coatings and raft-mounted machinery reduce acoustic signature significantly.

The Block-II variant—currently under construction—will feature improved sonar performance, longer range missiles via an extended VLS section (10 tubes), and potentially lithium-ion battery integration pending test results from Japan’s Soryu-class experience.

Operational or Strategic Context

The timing of this promotion is strategic. Canada has struggled with persistent availability issues in its Victoria-class fleet—originally acquired second-hand from the UK in the late 1990s—and has yet to finalize requirements or select partners for CPSP. With Arctic sovereignty concerns rising due to increased Russian and Chinese naval activity in high latitudes, Ottawa faces pressure to field a modern undersea deterrent by the early-to-mid 2030s.

Korea’s offer could appeal on several fronts:

• Maturity: The KSS-III is already operational with ROKN; two units commissioned since August 2021.
• AIP capability: Critical for extended patrols without surfacing—a key requirement for Arctic operations where stealth is paramount.
• No ITAR restrictions: Unlike U.S.-built systems that may be constrained by technology transfer rules.
• Bilateral ties: Strengthened defense-industrial cooperation could open doors for co-production or technology sharing under Canada’s Industrial Technological Benefits (ITB) policy framework.

Market or Industry Impact

If successful, a Canadian order would mark South Korea’s first major export win in the large-displacement SSK category—a segment traditionally dominated by European players like Germany’s TKMS (Type 212/214), France’s Naval Group (Scorpène), and Sweden’s Saab Kockums (A26). It would also reinforce Hanwha Ocean’s transformation from domestic supplier into a global competitor following its acquisition by Hanwha Group in May 2023.

The global market for advanced non-nuclear submarines is projected to exceed $40 billion over the next decade. Countries such as India, Indonesia, Brazil, Poland, Norway, and Australia are all evaluating next-generation SSK platforms amid rising maritime tensions. According to Milivox analysis, KSS-III’s blend of size, strike capability via VLS integration, and indigenous systems makes it uniquely positioned among NATO-compatible offerings outside Europe or Japan.

Milivox Commentary

This outreach effort reflects both opportunity and urgency. For South Korea, promoting the KSS-III aligns with President Yoon Suk Yeol’s push for greater self-reliance in defense exports—a goal underscored by recent deals involving FA-50 fighter jets and Redback IFVs abroad. For Canada, it offers an alternative path that avoids long procurement timelines associated with European shipyards already burdened by domestic orders or political constraints tied to U.S.-based designs like Virginia-class SSNs discussed under AUKUS Pillar II concepts—which remain speculative at best for Ottawa’s needs.

As assessed by Milivox experts, while technical compatibility remains promising—including potential interoperability within NATO ASW frameworks—the real challenge will be political alignment within Canada’s procurement bureaucracy. Still reeling from past missteps such as delays in CSC frigates and fighter jet replacements, Ottawa must weigh risk versus readiness carefully if it seeks credible deterrence beneath Arctic waters before mid-century.