China’s understated unveiling of a new underwater commando craft in Saudi Arabia is drawing fresh attention to how Beijing is fusing special operations warfare with an increasingly assertive global arms-sales strategy.
Earlier this month, the South China Morning Post reported that China’s state-owned shipbuilding giant China State Shipbuilding Corporation (CSSC) provided a rare overseas glimpse of a secretive underwater combat vehicle at a major defense exhibition in Saudi Arabia. The appearance of the platform — designated SDV-01 — marked an unusual public display of a capability that has previously remained largely in the shadows.
The SDV-01 is described as a surface-to-subsurface “swimmer delivery vehicle,” or SDV, designed to covertly transport multiple frogmen for missions such as combat diving, underwater demolition and reconnaissance. According to the report, the model’s presence at the Saudi show underscores Beijing’s intent to market increasingly sophisticated naval systems to Middle Eastern buyers, at a time when Gulf security anxieties remain high and competition among arms suppliers is intensifying.
Operational details surrounding the SDV-01 remain scarce. Prior to its appearance in Saudi Arabia, public confirmation of the craft was limited to a brief 2018 Chinese state television segment showing a similar vehicle being launched from either a submarine or a surface ship. Even then, technical data and doctrinal context were left largely unexplored.
More granular specifications surfaced later in specialist reporting. In November 2023, Naval News described the SDV-01 as a “wet” submersible capable of carrying up to eight frogmen and their equipment in an enclosed cabin. The platform reportedly features independent diver hatches and provides at least eight hours of air supply for embarked personnel.
Measuring 8.9 meters in length and 1.5 meters in diameter, the SDV-01 displaces no more than 4.5 tons. It can reportedly reach speeds of up to 10 knots while submerged. The vehicle is said to normally operate at depths of around 10 meters, with a maximum operating depth of 40 meters. Navigation is described as a blend of satellite, inertial and Doppler systems, integrating China’s BeiDou positioning network and acoustic communications. Both manual and automatic control modes are reportedly available.
Even with these details, much remains unclear — including which variant, if any, is currently fielded by the People’s Liberation Army Navy (PLAN), and whether the model shown abroad represents a fully operational configuration or an export-optimized design.
At the tactical level, the SDV-01 functions as a key enabler for clandestine maritime operations. Its primary advantage lies in its ability to move beneath surface surveillance during the narrow window between detection and engagement, allowing special operations teams to approach contested shores, insert onto sensitive targets or extract undetected.
Unlike submarines designed for strategic deterrence or sea denial, swimmer delivery vehicles are tools of preparation and disruption. They are built not for decisive fleet battles, but for reconnaissance, sabotage, target designation and obstacle clearance — the kinds of actions that can soften defenses and create opportunities for larger follow-on forces.
Western assessments of Chinese doctrine suggest that this preparatory role is central to how Beijing envisions special operations forces (SOF) functioning in high-intensity contingencies.
In a January 2022 report for the China Maritime Studies Institute, analysts John Chen and Joel Wuthnow argued that China’s SOF, including naval frogmen, are intended to infiltrate ahead of a main amphibious landing force in a Taiwan scenario. Using special mission craft, submarines or helicopters, these teams would conduct reconnaissance of beaches and approaches, clear obstacles, attack key nodes such as ports and radar installations, guide precision strikes and disrupt command-and-control structures before and during a landing.
In that framework, a platform like the SDV-01 is not an accessory but a core enabler. By quietly inserting frogmen onto contested shores or critical infrastructure, the vehicle could help shape the battlefield before conventional units arrive.
The logic underpinning such capabilities extends beyond a potential Taiwan campaign. Analysts writing in the October 2025 issue of Small Wars Journal outlined how PLA special operations forces could conduct rapid “micro-occupation” seizures of specific Philippine-held or claimed features in support of a Taiwan contingency.
Chad Machiela and co-authors argued that Mavulis Island, located at the northern tip of the Philippines, could be seized within hours by PLA SOF to position sensors and missile systems controlling the Bashi Channel — a critical chokepoint between the South China Sea and the Philippine Sea. They suggested that heliborne or amphibious forces could similarly take Itbayat and Batan (Basco) to establish forward operating bases.
The same analysis described coercive takeover playbooks for disputed features such as Second Thomas Shoal, Scarborough Shoal and Sabina Shoal, using maritime militia units backed by follow-on forces to establish faits accomplis. The goal in such scenarios would not be a dramatic, large-scale assault but a rapid, limited seizure that presents opponents with a dilemma: escalate or accept the new reality.
In Japan, concerns over similar gray-zone tactics center on the Senkaku Islands in the East China Sea. Writing in June 2021 for the Japan Foreign Policy Forum, analyst Watanabe Tsuneo argued that a Chinese takeover of the islands would most plausibly occur not through a conventional amphibious assault, but via a gray-zone operation involving special forces or maritime militia. Personnel could secretly land, raise the Chinese flag and refuse to withdraw, exploiting legal and response gaps to delay Japan’s Self-Defense Forces while consolidating control.
Such scenarios illustrate how platforms like the SDV-01 fit into a broader doctrinal ecosystem that emphasizes stealthy insertion, deniable presence and rapid faits accomplis.
The decision to showcase the SDV-01 in Saudi Arabia is significant. The kingdom sits astride vital maritime routes linking the Persian Gulf to global energy markets. The Strait of Hormuz, in particular, has seen periodic tanker seizures, drone incidents and missile drills involving Iran and regional actors.
For Gulf states, protecting critical shipping lanes and offshore infrastructure requires a layered approach, including surveillance, patrol craft, coastal defense missiles and special operations capabilities. Swimmer delivery vehicles could offer a means to conduct covert inspections, counter-sabotage missions or discreet reconnaissance in sensitive littoral zones.
By presenting the SDV-01 alongside export-oriented amphibious and submarine models, CSSC signaled a broader ambition: to offer a more “systematic” naval export portfolio. Rather than marketing isolated platforms, China appears intent on packaging a full-spectrum maritime toolkit — from major surface combatants to niche special operations craft.
This aligns with a pattern seen in other regions, where Beijing combines hardware sales with training, maintenance packages and long-term industrial partnerships. Chinese defense firms often highlight fewer political conditions and faster delivery timelines compared to Western suppliers, an attractive proposition for states facing restrictions or delays in acquiring US or European systems.
China’s expanding footprint in Middle Eastern defense markets is not merely commercial. Arms sales serve multiple strategic functions: deepening bilateral ties, creating long-term dependencies through maintenance and spare parts, and normalizing Chinese standards and doctrines within partner militaries.
The display of advanced, relatively opaque technology such as the SDV-01 also signals confidence in the maturity of China’s defense industrial base. Even if sales volumes remain limited, the symbolic value of presenting such systems abroad reinforces Beijing’s image as a provider of cutting-edge capabilities.
At the same time, exporting gray-zone tools carries potential consequences. Swimmer delivery vehicles and similar systems are inherently suited to ambiguous operations that blur the line between peace and conflict. In volatile regions like the Gulf, their proliferation could complicate maritime security calculations and heighten suspicion among rival states.
None of this guarantees that the SDV-01 will become a staple of Middle Eastern navies. The system remains opaque, its operational track record unknown and its performance untested in open-source scrutiny. Potential buyers will weigh factors such as reliability, interoperability with existing fleets and the political implications of deepening defense ties with Beijing.
Yet the significance of the Saudi unveiling lies less in immediate sales prospects and more in what it reveals about Chinese priorities. Beijing is choosing to showcase not only large surface combatants and submarines, but also the tools of stealthy insertion and special operations.
That choice reflects an understanding that modern maritime competition often unfolds below the threshold of open war. In contested waters — whether around Taiwan, in the South China Sea or near strategic chokepoints in the Middle East — small, deniable actions can have outsized strategic effects.
By linking special operations warfare with a global arms-sales push, China is effectively exporting not just platforms, but a way of war built around ambiguity, speed and the creation of new facts on the ground — or beneath the waves — before rivals can respond.
As more states assess their vulnerabilities to gray-zone tactics, the quiet debut of the SDV-01 in Saudi Arabia may prove to be more than a niche product launch. It could mark another step in the diffusion of a maritime strategy that prizes stealth and incremental advantage over dramatic confrontation — reshaping not only how wars might be fought, but how they are deterred.
