Sealien raises over RMB 500 million: BYD is an existing investor, while Phoenix 600 has reached overseas commercial deployment

Sealien (Deep-sea Zhiren) is a Guangzhou-based company focused on work-class deep-sea robots and intelligent marine equipment. On 13 August 2026, it announced a Series A financing of more than RMB 500 million. The significance of the round lies not only in its size, but also in the combination of commercial venture capital, state-linked investors and energy-industry capital. The company had also already achieved a major overseas commercial milestone with its Phoenix 600 system. 139

Who invested in the round?

Public reports identify the following new shareholders:

• Photosynthesis Ventures
• Fortune Capital
• GGV Capital
• Addor Capital
• China Insurance Investment
• CETC Investment
• An energy-technology fund managed by Cathay Capital, with TotalEnergies as a contributing investor

Existing shareholders including Zhengxuan Investment, Yunze Capital, Yunshi Capital, Gaojie Capital and Xingzhi Capital also reportedly made substantial follow-on investments. The investor mix suggests that this was not a single-fund deal: major venture-capital firms, state-linked investment institutions and energy-sector capital all placed bets on deep-sea industrial equipment. 137

Did BYD participate in this financing?

BYD Group has been reported as an existing investor in Sealien, alongside GGV Capital, Lightspeed China, ECC Capital, Shenzhen Investment Holdings, Guangzhou Fund and Seas Capital. 1

However, the available reporting does not provide sufficient evidence that BYD was a new investor, lead investor or confirmed participant in the August 2026 Series A. The more accurate conclusion is therefore: BYD had invested in Sealien previously, but its participation in this particular round has not been established.

What is Sealien, and why do sources cite different founding dates?

Headquartered in Guangzhou’s Nansha district, Sealien develops equipment for industrial applications including offshore oil and gas, subsea communications, offshore wind and other deep-sea operations. Its products include work-class remotely operated vehicles (ROVs), subsea cable-trenching robots, general-purpose marine robots and related intelligent systems. 369

The company’s founding date is reported inconsistently. Several August 2026 reports say it was founded in 2020, while corporate-information pages cite 2021 as the establishment date or the beginning of operations. A cautious description is that the company’s registered entity can be traced to 2020, while some business and external-development milestones are described as beginning in 2021 or 2023. 3101920

Why did founder Ma Yiming pursue domestic deep-sea robots?

Founder Ma Yiming studied naval architecture and ocean engineering at Harbin Engineering University. Public reports say he later became the first Chinese engineer at European deep-sea robotics supplier SMD and participated in a commercial deep-sea-mining robot project. 3510

The gap he described was not limited to a single component or performance specification. It involved the entire industrial system behind deep-sea equipment: design standards, supply-chain management, testing and validation, engineering production and project delivery. Reports about his experience at an overseas deep-sea robot production site describe how reliability under extreme pressure, standardized processes and repeatable delivery mattered as much as individual technical parameters. 18

That background helps explain Sealien’s strategy. The company is not presenting its ambition merely as building a robot that can descend into the ocean. It aims to control the broader chain—from complete-machine design and key systems to manufacturing and delivery—while reducing dependence on imported core technologies. Multiple reports say Sealien can independently develop and manufacture many core components and systems, apart from standard parts and some acoustic sensors. However, different sources use different definitions for the company’s localization ratio and “full-stack autonomy,” so those claims should be treated carefully. 32125

From a single ROV to subsea robot clusters

Sealien’s product and technology roadmap can broadly be understood in three layers:

1. Work-class underwater robots: ROVs used for deep-sea observation, manipulation and engineering operations;
2. Cable-trenching equipment: robots for burying submarine optical cables, oil-and-gas umbilicals and related subsea lines;
3. Autonomous systems: including autonomous underwater vehicles (AUVs), the Deep Matrix resident subsea robot-cluster concept and the SEAgent task-decision system.

Public reports describe Deep Matrix as a combination of “resident subsea robot hardware” and a task-decision model. Its goal is to enable multiple underwater devices to coordinate long-duration missions with less direct human intervention. 67841

The phrase “L4 autonomy” is better understood at this stage as a stated target or promotional description, rather than as a system-level certification independently verified by technical documentation. The available reporting does support a shift from manually controlled single-machine operations toward human-robot collaboration, multi-robot coordination and more autonomous task execution. 714

What can SEAgent 1.0 do?

Sealien introduced SEAgent 1.0 in spring 2026. The company and related reports describe it as an underwater multi-agent task-decision model. Sources differ on the exact launch timing, citing March, April or May. 174142

Its role is not simply to make a robot “understand a sentence.” Rather, it is designed to translate natural-language requests into structured tasks that underwater equipment can execute. Public descriptions include the following steps:

• identifying the operator’s intent;
• using multi-turn dialogue to obtain missing information such as location, target, time window and operational objective;
• converting incomplete, non-standard or non-engineering language into structured instructions;
• reorganizing task logic when requirements change; and
• assessing whether a task fits the equipment’s capabilities, environmental conditions, communication status and safety constraints.

For example, an operator might give a relatively vague instruction to inspect corrosion on an underwater facility. The system could then combine maps, equipment records and predefined task templates to turn “check the corrosion” into a more specific set of inspection steps. 4142

Some reports go further, saying that SEAgent can flag risks, request additional conditions or suggest adjustments when an instruction exceeds the equipment’s capabilities, violates safety limits or conflicts with the operating environment. That direction is consistent with the demands of deep-sea work, but the public material does not yet prove that the system has a broadly applicable, independently validated ability to reject every unsafe instruction.

For now, the most precise description is that SEAgent is an entry point for task understanding, task admissibility assessment and collaborative decision-making in deep-sea operations, rather than a fully verified unattended-autonomy system. 114

Which products are publicly confirmed?

The products most consistently identified across sources are:

• Singularity (奇点): a work-class robot rated for operations down to 6,000 metres;
• Phoenix (凤凰座): a buoyancy-capable work-class robot rated for operations down to 3,000 metres;
• Taurus (金牛座): a heavy-duty cable-trenching robot rated for operations down to 1,000 metres.

Together, these products cover applications ranging from deep-sea work-class ROV operations to subsea cable installation. 367

Other reports mention robots or products named Aquila, Phoenix, Taurus, Pisces, Scorpio and Sagittarius. But sources do not consistently agree on their product classifications, model relationships or commercial status. The full six-name constellation list should therefore not yet be treated as a completely confirmed commercial catalogue. 10192426

Why is Phoenix 600 important?

Phoenix 600 is one of Sealien’s most prominent commercial products. Available information describes it as a 3,000-metre-class, buoyancy-capable subsea cable-trenching ROV system comprising the robot itself, a launch-and-recovery system, control equipment and electrical systems.

Reports commonly describe the system as approximately 6 metres long and around 12 tonnes, with the ability to bury submarine optical cables at centimetre-level precision. Some technical material says its maximum burial depth can reach 3 metres. 212731

The specifications vary between sources. Some reports cite a weight of 8 tonnes, others 12 or 13.5 tonnes, possibly reflecting different measurement scopes for the robot body and the complete system. The available evidence does not firmly confirm the precise dimensions of 6.2 × 3.8 × 3 metres, nor does it establish a uniform “L3 intelligent operations” certification. A more cautious description is therefore: approximately 6 metres long, about 12 tonnes, suitable for depths of up to 3,000 metres and capable of centimetre-level optical-cable burial precision. 21252734

The commercial export milestone behind the financing

In 2025, Sealien delivered a Phoenix 600 to a subsea-cable contractor affiliated with a UAE telecommunications group. The order was reported to be worth nearly US$10 million. Several media outlets described the delivery as the first commercial export of a domestically produced Chinese deep-sea robot. 222732

The UAE customer later made a follow-on purchase. Reports also say Sealien serves international oil-and-gas contractors, subsea telecommunications and cable contractors, and offshore-wind contractors. The company has carried out business in overseas markets including the United Kingdom and the UAE; some sources list a wider group of countries, although not all customer and order details have been independently verified. 41130

The importance of this export lies in the nature of the product. Deep-sea robots are not ordinary hardware. They require prolonged validation, vessel integration, offshore construction experience and after-sales support. Phoenix 600’s entry into an overseas commercial project indicates that Sealien has moved beyond a research prototype toward complete-machine sales and engineering delivery.

The next test is whether the company can scale delivery, maintain reliability and build an effective overseas service network after the financing. Those execution questions may matter as much as the underlying technology. 4

What is this financing really backing?

The more significant story behind Sealien’s Series A is not simply the expansion of one robot model. The funding supports a broader deep-sea equipment and intelligence roadmap: work-class ROVs, cable-trenching machines and AUVs on one side, and the Deep Matrix resident robot-cluster concept and SEAgent task-decision system on the other.

The facts that can be stated with the greatest confidence are that Sealien completed a financing of more than RMB 500 million, attracted a combination of major VC firms and industrial investors, counts BYD among its existing investors, and has already achieved commercial overseas delivery with Phoenix 600. Its publicly reported main products span operating depths from 1,000 to 6,000 metres.

Claims about L4 autonomy, a complete six-product constellation, Phoenix 600’s exact dimensions and an L3 capability should be treated as provisional until supported by fuller company technical documentation, certification records or independent testing.