The industrial chain of marine equipment is extensive and complex, playing a vital role in ensuring the security of the marine economy. In China, part of the marine equipment market and orders are based abroad, and some of the core technologies and ancillary equipment rely on imports. Once affected by the international situation, the industrial chain might be cut off. Therefore, it is necessary to promote the independent and innovative development of the marine equipment, thereby ensuring the industry chain safety and high-quality development of marine equipment. This study proposes a marine equipment industry chain map. Focusing on the marine transportation equipment and the offshore oil and gas equipment, it analyzes the development status of the marine equipment industry chain in China and abroad, clarifies the development situation and problems regarding major links of the marine equipment industry chain in China, and proposes the principles, goals, and breakthrough directions. Raw materials and the final assembly are advantageous links for China, while equipment design and ancillary equipment are weak links; In particular, China's independent support capabilities for high-tech ships and deepwater oil and gas development equipment are insufficient. Therefore, it is necessary to stimulate the domestic demand for marine equipment through policy support, focus on the advantageous innovation direction of high-end marine equipment, and strengthen international cooperation.

Advancing the deep-sea floating wind power technology is an effective pathway to reducing costs and enhancing efficiency in offshore wind power development, driving structural reforms in the energy system, and achieving the carbon peaking and carbon neutralization vision. Therefore, achieving breakthroughs in core technologies regarding deep-sea floating wind power and accelerating the construction of cost-effective offshore wind power systems have become major tasks in China's energy and electricity fields. This study reviews the development status of deep-sea floating wind power in China and abroad, analyzes the challenges faced by China's deep-sea wind power industry, and explores the key elements for technological breakthroughs in deep-sea floating wind power, involving key scientific issues, core technologies, and basic software capabilities (e.g., integrated coupling design and analysis and real-time digital twin systems). Specifically, the key scientific issues include evolution of aerodynamic loads on wind turbines, motion suppression for semi-submersible foundations, resonance of tension-leg-platform-type foundations, and testing across physical fields. The core technologies include aerodynamic modeling of wind turbines, integrated coupling analysis, structural fatigue analysis, mooring and dynamic cable analysis, load capacity analysis for mooring foundations, advanced material development and testing, large-scale customization of foundation structures, integration and offshore installation and reconnection, and intelligent operation and maintenance (O&M). Additionally, the technical development directions of deep-sea floating wind power technology are elaborated, including different types of floating foundations, overall design of floating wind turbines, independent research and development of key products, core industrial software, efficient construction and installation, and intelligent O&M. Furthermore, it is proposed to establish a technological innovation chain, form an intelligent construction and installation chain, and expand the intelligent O&M system for deep-sea wind power, providing forward thinking for the research and engineering application of the deep-sea floating wind power technology in China.

As key equipment connecting offshore platforms to subsea pipelines, marine risers are a critical component of the overall system for deepwater oil and gas exploitation and are crucial for the high-quality development of the marine oil industry. In the context of attaching more attention to the development of deepwater oil and gas resources, this study reviews the research and application of marine risers in deepwater oil and gas development and looks forward to future development, which has reference values for both theoretical research and engineering practices. In this paper, the strict requirements for service performances of marine risers are analyzed in terms of fatigue resistance and corrosion resistance. ​A review of the current status of three typical and widely used marine risers (i.‍e., drilling risers, steel catenary risers, and tension-leg platform tendon risers) is provided. Meanwhile, these marine rises in China and abroad are compared, and their development directions are prospected. Overall, marine risers are a type of oil drilling equipment that have high risks, extreme difficulty, and high added values. Owing to the complex manufacturing processes and high technical contents, the core materials and technologies of marine risers have been monopolized by large companies outside China. Riser materials of China have problems including large fluctuations in strength, low fracture toughness, and insufficient fatigue resistance, failing to meet the stringent and complex marine service conditions and thus restraining the development of China's offshore oil industry. Therefore, a systematic layout is urgently needed to guide upstream and downstream enterprises to jointly carry out basic and application research on related products with universities and research institutes, so as to realize collaborative innovation across the entire industrial chain of marine riser manufacturing.

"Carbon capture ashore and storage offshore" has been one of the important application scenarios in carbon capture, utilization and storage (CCUS) solutions in recent years. It is forward-looking and urgent to clarify the development orientation, application prospect, and implementation pathway of "carbon capture ashore and storage offshore" in China in the context of carbon neutrality. This study reviews the progress of "carbon capture ashore and storage offshore" from the perspectives of process characteristics, development potentials, international projects progress, and planning research progress in China. Based on analyses of the development prospects, this study explores the challenges and countermeasures of "carbon capture ashore and storage offshore" in China from the aspects of economic cost, leakage risk, storage efficiency, policy management, and international situation. The development of "carbon capture ashore and storage offshore" in China can be divided into three stages: project planning and research, small-scale demonstrations, large-scale commercial application, and the development timeline toward 2060 is predicted. Accordingly, it is recommended to focus on key development milestones and timely introduce supportive policies. A comprehensive regulatory system should be established to enhance risk prevention and control. Small-scale pilot projects should be initiated to prudently drive industrialization. The market's pivotal role should be leveraged, with enterprises leading commercial applications. Through scientific planning and steady advancement of "carbon capture ashore and storage offshore" initiatives, robust support can be provided for China to achieve its goal of carbon neutrality.

The ocean harbors abundant solid minerals and is the world’s largest carbon sink with vast carbon sequestration potentials. Exploring the synergistic development of deep-sea mining and carbon sequestration is of significant importance for supporting China’s green and low-carbon transformation in deep-sea mining, as well as enhancing its influence in the field of ocean development and governance. This study summarizes the development status and trends of deep-sea mining operational models, focusing on the efficient, green, and low-carbon development of deep-sea mineral resources. It proposes synergistic operations that integrate deep-sea mining with marine carbon sequestration, creating a dual-industry collaborative development model. From the perspectives of feasibility, synergy, and economic viability, the competitiveness of a "deep-sea mining + carbon sequestration" model is analyzed. Breakthrough directions and technology development pathways are proposed, including efficient integration of deep-sea mining and carbon sequestration systems, environmental impact monitoring, carbon footprint tracing, and collaborative operation equipment. Research findings indicate that CO₂ jets in deep-sea mining environments exhibit a collection performance comparable to water jets, along with better environmental friendliness and lower risks of carbon sequestration leakage. Deep-sea mining and marine carbon sequestration show high complementarity in terms of operational equipment and space, with no interference in their operational cycles. This industrial collaborative development model can improve the profitability of both marine carbon sequestration and deep-sea mining. To promote the synergistic development of these two industries, it is essential to accelerate breakthroughs in core deep-sea technologies and equipment, establish a complete industrial chain and clusters, and foster the comprehensive development of compound talent teams, technical equipment, and economic benefits in deep-sea mining and marine carbon sequestration.

With the further development of deep-space, deep-sea, and deep-ground technologies, numerous technical connections are found existing between deep-sea engineering and deep-space exploration and thus it is feasible to apply deep-sea engineering technologies to deep-space exploration. By comparing the environmental characteristics of deep space and deep sea, this study reveals the similarities between deep-sea engineering and deep-space exploration in terms of pressure and temperature adaptability. Then, it explores the prospects on structural safety, complex operation technology and equipment, unmanned intelligence and miniaturization of loads, and construction of test sites. It is found that the physical characteristics of the extraterrestrial space is prominently diversified, and the environment of some hotspot planets is similar to that of the deep sea in terms of pressure and corrosion. Therefore, the structure design and anticorrosion technologies regarding deep-sea engineering can be applied to deep-space exploration. Meanwhile, the requirements for complex control and unmanned automation of deep-space exploration equipment are consistent with those of deep-sea engineering equipment; therefore, the research and development of specific equipment from these two fields are interchangeable. The submarine volcanic areas and the Antarctic subglacial lake (i.e., Lake Vostok) have obvious extraterrestrial space characteristics and can be established as test sites for deep-space exploration, which can be regarded as a research direction for deep-sea test sites and new test technologies for deep-space exploration. To sum up, technology exchange and cross-domain application between the deep-sea and deep-space technologies are highly possible, and the full application of deep-sea engineering technologies to deep-space exploration will help China’s deep-space exploration equipment develop faster.