The conflict between populations, resources, and the environment in the 21st century has made the ocean a strategic space and resource treasure for human society to realize sustainable development. In order to study the ocean environment and exploit ocean resources, a fundamental understanding of complex and interwoven ocean processes across a broad range of spatial and temporal observational scales is required.

This understanding is heavily reliant on various research fleets and equipment to support increasingly complex, multidisciplinary, multi-investigator research projects, including those in support of autonomous technologies, ocean observation systems, process studies, remote sensing, and modeling. Various underwater submersibles are the main working force for research fleets.

The following Special Issue includes 12 research works that cover four critical areas: the wireless power transfer systems of autonomous underwater vehicles (AUVs), the water entry dynamics of freely falling unmanned aerial-underwater vehicles and the descent dynamics of benthic landers, the connectors utilized in subsea production systems, and cleaning equipment designed to combat fouling on marine steel piles. Each one of these subjects represents a key technological challenge to be addressed in the ongoing development of deep-sea equipment.

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