At present, there is no international instrument to provide significant legal protection to underwater cultural heritage -- shipwrecks, sunken cities, underwater cave paintings, and so forth. Although some nations possess laws to provide protection in their own waters, others don't. This has led to confusion about the rights of a nation to protect its cultural heritage, whether submerged in its own waters or another nation's, or on the high seas.
This could soon change. From October 15 through November 3 of this year, the General Conference of the United Nations Educational, Scientific, and Cultural Organization (UNESCO) will meet to discuss, among other things, the adoption of a draft convention for the protection of underwater cultural heritage. If adopted by a two-thirds majority of UNESCO member nations, the draft convention would become international law, at least for its signatories.