First, can the environmental protection functions required under the existing international framework be maintained at an equivalent level under this distributed operational structure? Second, to what extent may coastal states regulate before an incident and enforce after one in the territorial sea, without impairing innocent passage or shifting the allocation of jurisdiction established by the United Nations Convention on the Law of the Sea (UNCLOS)? The timing of the analysis reflects a shifting regulatory landscape.

Although the scale and schedule of commercial deployment remain uncertain, the international community has adopted a non-mandatory MASS Code in 2026, alongside a planned experience-building process at the International Maritime Organization. These developments signal that remotely operated shipping is now a matter of active rule-making rather than pure speculation, even as binding obligations for crewless vessels remain unsettled. Using doctrinal and interpretive analysis of UNCLOS, relevant IMO instruments, the MASS Code and international case law, the study distinguishes measures available under existing law from areas that would require further normative development.

Its central argument is that functional equivalence should not be treated as an independent basis of coastal state jurisdiction. Instead, it should serve as an analytical criterion for assessing whether the existing level of marine environmental protection is effectively maintained when human and informational functions are performed remotely rather than on board. At the pre-incident stage, the authors propose common international criteria for judging whether the pollution-response chain remains intact: effectiveness, timeliness, continuity and reliability, fallback capability, and external verifiability.

Under this framework, coastal state measures must remain within existing jurisdictional limits and satisfy the established requirements of necessity, proportionality, non-discrimination and consistency with innocent passage. The post-incident picture is more granular. The study treats orders to stop a vessel, the measures used to compel it to stop, remote verification and physical inspection, detention, and the preservation and acquisition of digital evidence as legally distinct actions.

Each, the authors argue, requires its own legal basis, triggering conditions and procedural safeguards, rather than being bundled into a single enforcement power. The article's conclusion is deliberately restrained: the principal regulatory task is not to create new coastal state powers for MASS, but to clarify how existing environmental protection and enforcement functions can operate effectively when the relevant human and informational roles are performed remotely.

Subject of Research: Legal analysis of innocent passage and coastal state jurisdiction over remotely operated autonomous ships under UNCLOS

Article Title: Innocent passage and marine environmental protection of remotely operated MASS: functional equivalence and coastal state jurisdiction

Article References: Jang, Y., & Yu, Y. (2026). Innocent passage and marine environmental protection of remotely operated MASS: functional equivalence and coastal state jurisdiction. Frontiers in Marine Science, 13, Article 1980641. https://doi.org/10.3389/fmars.2026.1980641

Image Credits: AI Generated

DOI: 10.3389/fmars.2026.1980641

Keywords: Maritime Autonomous Surface Ships, MASS Code, UNCLOS, innocent passage, coastal state jurisdiction, marine environmental protection, ship-source pollution, remote operations centre, International Maritime Organization, territorial sea, maritime law, autonomous shipping