China Conducts 43 Arctic Manned Dives with Dual Submersibles, Signaling Strategic Under-Ice Capability

Milivox analysis: China’s successful execution of 43 manned dives under Arctic ice using two deep-sea submersibles marks a significant leap in polar operational capability. The dual deployment of HOV Fendouzhe and Deep Sea Warrior demonstrates not only technical maturity but also strategic intent in contested polar regions.

Background

In a major milestone for its deep-sea exploration program, China completed a series of 43 manned dives beneath the Arctic ice cap between March and May 2025. The missions were conducted aboard two domestically developed human-occupied vehicles (HOVs): Fendouzhe (“Striver”) and Shenhai Yongshi (“Deep Sea Warrior”), operating from the research vessel Zhang Jian. This marked the first time China deployed two manned submersibles simultaneously under polar ice conditions—a feat previously accomplished only by the United States and Russia.

The operation was part of China’s broader “Jiaolong into the Sea” initiative—a multi-year campaign aimed at developing indigenous deep-sea capabilities for scientific research, resource mapping, and strategic presence in key maritime domains. According to Chinese state media and corroborated by gCaptain’s report on June 3rd, these missions included dives as deep as 1,500 meters beneath thick multiyear sea ice near Svalbard and other high-latitude locations.

Technical Overview

The two submersibles involved—Fendouzhe and Deep Sea Warrior—represent China’s most advanced manned underwater platforms:

• Fendouzhe (Striver): Capable of diving to depths exceeding 10,000 meters (10,909 m achieved in Mariana Trench in 2020), it is among the world’s deepest-diving crewed submersibles. It features an advanced titanium pressure hull rated for full ocean depth operations.
• Deep Sea Warrior: Operational since 2017 with a maximum depth rating of ~4,500 meters. It uses domestically developed lithium battery systems and life-support modules designed for extended missions.

The joint deployment required significant engineering coordination to operate both vehicles from a single mother ship under extreme cold-weather conditions. Challenges included:

• Navigating through drifting pack ice without GPS or surface communications;
• Sustaining life support systems during prolonged dives beneath thick ice sheets;
• Synchronized launch/recovery cycles from RV Zhang Jian within narrow weather windows;
• Icing mitigation on deck equipment and launch gantries.

This dual operation underlines China’s growing confidence in its indigenous subsea technologies—especially pressure-resistant materials, inertial navigation systems (INS), acoustic modems for under-ice comms, and cold-environment battery performance.

Operational or Strategic Context

The timing and location of these operations are geopolitically significant. The Arctic region is increasingly viewed as a domain of strategic competition due to its untapped hydrocarbon resources, critical shipping lanes (e.g., Northern Sea Route), and military relevance for submarine-based deterrence strategies.

Milivox reports that China’s increasing presence in the High North aligns with its designation as a “near-Arctic state”, despite lacking territorial claims north of the Arctic Circle. These dive operations serve multiple overlapping objectives:

• Dissuasion & ISR: Demonstrating ability to conduct ISR or seabed mapping missions under NATO air/naval coverage zones;
• Dual-use R&D: Advancing civilian oceanographic research while validating technologies applicable to future PLA Navy underwater assets;
• Cable & Infrastructure Mapping: Potential reconnaissance of subsea cables or infrastructure relevant to Western communications resilience;
• Tactical Familiarity: Gaining operational experience in acoustically complex environments where U.S., UK or Norwegian SSNs may patrol.

Market or Industry Impact

The success of this mission will likely accelerate Chinese investment into dual-use maritime technologies—including autonomous underwater vehicles (AUVs), seabed sensors, modular payload bays for ISR tasks, and cryogenic-resistant materials manufacturing. It also signals potential export ambitions for Chinese-built submersibles to friendly nations seeking access to deep-sea exploration without relying on Western suppliers.

This development may influence procurement decisions across allied navies regarding anti-submarine warfare (ASW) postures in polar regions. For instance:

• NATO may increase sonar net deployments or under-ice UUV patrols near Greenland-Iceland-UK Gap (GIUK);
• Northern European navies could seek enhanced cooperation on seabed domain awareness (SDA);
• The U.S. Navy might revisit its own manned/unmanned polar-capable platforms beyond Seawolf-class SSNs.

Milivox Commentary

“These are not just science dives,” assessed one Milivox naval analyst. “They are proof-of-concept demonstrations that China can operate persistently—and with redundancy—under some of Earth’s most inaccessible waters.”

This capability mirrors Cold War-era Soviet efforts such as Project 10831 (“Losharik”) which aimed at seabed manipulation and cable tapping at extreme depths. While China has not publicly acknowledged any military applications tied directly to these platforms, their performance metrics suggest clear relevance for future seabed warfare scenarios—especially given recent global focus on subsea infrastructure vulnerability post-Nord Stream sabotage events.

As assessed by Milivox experts, this operation represents more than engineering prowess—it is an assertive signal that Beijing seeks parity with major naval powers across all maritime domains: surface, subsurface—and now increasingly—under-ice environments once considered exclusive bastions of NATO/Russian capability dominance.