The maritime regions of Northeast Asia are repositories of rich yet vulnerable underwater cultural heritage (UCH). This shared legacy transcends national boundaries, presenting a complex governance challenge. A comparative analysis of the three states reveals significant divergence in their domestic legal regimes concerning key issues: the definition and scope of protected heritage, the assertion of ownership and jurisdictional rights, approaches to management in disputed maritime zones, and the sensitive status of sunken state vessels. These policy disparities, set against a backdrop of geopolitical tension and an ineffective international legal framework, critically undermine coordinated protection efforts. This article systematically maps these policy differences to argue that the very necessity of trilateral cooperation stems directly from this comparative landscape of divergence. It concludes that establishing a collaborative governance framework is not merely a diplomatic aspiration but a pragmatic imperative for the effective safeguarding of this common regional heritage.

Ⅰ. Introduction
II. Heritage Value and the Imperative forPreservation
    A. Dual Origins of Heritage: Historical Trade Networks andNaval Conflict Sites
    B. Beyond Archaeology: The Socio-Political Significance of Shared Maritime Heritage
    C. From Degradation to Looting: The Imperative forCoordinated Protection
III. International Legal Frameworks on the UCH Protection in Northeast Asia
    A. The UNCLOS: Principled Provisions and Ambiguities
    B. The UCH Convention: Progress and Gaps
IV. Domestic Legislation in China, Japan,and Korea: A Comparative Analysis
    A. Overview: Divergent Legislative Approaches andPrinciples
    B. Comparative Criteria for Defining and Selecting ProtectedObjects
    C. Divergent National Regulations on Ownership and Rights
    D. Inconsistent Rules on Jurisdiction
    E. The Challenge in Disputed Maritime Zones
    F. The Legal Status of Sunken State Vessels
Ⅴ. Pathways Forward: Cooperative Solutions and Future Prospects
    A. The Necessity and Feasibility of International Cooperation
    B. Assessing Feasible Models for Northeast Asia
    C. Moving beyond Political Suspicion
Ⅵ. Conclusion

• Hui Zhong(Associate Professor of Law at Xiamen University Law School)
• Eric Yong Joong Lee(Professor of International Law at Dongguk University-Seoul, Korea) Corresponding author