It seems from the article below that Britain could still act against non-Britons diving on, and certainly taking items from, Repulse and Prince of Wales. Presumably this would require proceedings in a national court of competent jurisdiction, such as an American court where the claim is against American nationals. Presumably Britain is also entitled to take direct naval action on the high seas to prevent access to its ships.
Sunken Warships and Military Aircraft
by J. Ashley Roach, Captain, JAGC, U.S. Navy (Ret.), Office of the Legal Adviser, U.S. Department of State.
(Material contained herein is made available for the purpose of peer review and discussion and does not necessarily reflect the views of the Department of the Navy or the Department of Defense.)
At the present time there is hardly any object which cannot be located and explored on the sea-bed. Sophisticated equipment can pinpoint any anomaly on the sea-bed, and advanced technology enables the lifting of most objects.2 This technology, pioneered for the exploration of natural resources, is now in use by salvors, marine archaeologists and marine historians, whose interests are not necessarily viewed as being compatible.3 The cost of this technology is dropping rapidly and can be used by “treasure hunters”, the main interest of many of whom is the recovery of commercially valuable material without regard to the methods of archaeological excavation.4 Furthermore, much of the underwater cultural heritage which remains unexplored is on the outer reaches of the continental shelf or on the deep sea-bed beyond the limits of coastal State jurisdiction over sunken shipwrecks which, under the LOS Convention, is limited to 24 miles from the baseline.5 There is, however, at present no multilateral treaty governing the treatment of sunken ships located in those areas beyond coastal State jurisdiction,6 nor is there any multilateral treaty governing the particular case of sunken warships or military aircraft. As described in the following paragraphs, there is, nevertheless, a moderately well-developed body of customary international law governing the treatment of sunken warships and military aircraft (as opposed to other vessels and aircraft not entitled to sovereign immunity).7
Warships, naval auxiliaries, and other vessels owned or operated by a State and used at the time they sank only on government non-commercial service, are State vessels.8 Aircraft used in military, customs and police services are State aircraft.9 International law recognizes that State vessels and aircraft, and their associated artifacts, whether or not sunken, are entitled to sovereign immunity.10
In addition, such shipwrecks and sunken aircraft are historical artifacts of special importance and entitled to special protections. Many such ships and aircraft have unique histories making them important parts of their country’s traditions.11 In addition, these ships and aircraft may be the last resting places of many sailors and airmen who died in the service of their nations. 12
The practice of States confirms the well-established rule of international law that title to such vessels and aircraft is lost only by capture or surrender during battle (before sinking),13 by international agreement, 14 or by an express act of abandonment, gift or sale by the sovereign in accordance with relevant principles of international law and the law of the flag State governing the abandonment of government property.15 Once hostilities have ended, belligerents do not acquire any title to such vessels or aircraft through the act of sinking them. Likewise, title to such vessels and aircraft is not lost by the mere passage of time.16
A coastal State does not acquire any right of ownership to a sunken state vessel or aircraft by reason of its being located on or embedded in land or the seabed over which it exercises sovereignty or jurisdiction.17 Access to such vessels and aircraft and their associated artifacts located on or embedded in the seabed of foreign archipelagic waters, territorial seas or contiguous zones, is subject to coastal State control in accordance with international law.18 It is the policy of most Governments to honor requests from sovereign States to respect, or to authorize visits to, such sunken vessels and aircraft.19
Access to sunken state vessels and aircraft and their associated artifacts located on or embedded in the continental shelf seaward of 24 miles from the baseline is subject to flag State control and is not subject to coastal State control.20 Access to sunken state vessels and aircraft and their associated artifacts located on or embedded in the seabed seaward of 24 miles from the baseline is subject only to flag State control. 21
[b]Except for opposing belligerents while hostilities continue, no person or State may salvage or attempt to salvage sunken state vessels or aircraft, or their associated artifacts, wherever located, without the express permission of the sovereign flag State, whether or not a war grave.22
Once hostilities have ended, sunken state vessels and aircraft containing crew remains are also entitled to special respect as war graves and must not be disturbed without the explicit permission of the sovereign.23
The flag State is entitled to use all lawful means to prevent unauthorized disturbance of the wreck or crash site (including the debris field) or salvage of the wreck.24[/b]
Disturbance of any shipwreck or crash site is necessarily a destructive process. In virtually every instance, once recovery activities are undertaken, the site cannot be restored or replicated. Any recovery effort which disturbs the site denies other properly authorized persons the opportunity for scientific discovery and study.25
Accepted principles of marine archaeology, naval history and environmental protection require thoughtful research design, careful site surveys, minimal site disturbance consistent with research requirements, adequate financial resources, preparation of professional reports, and a comprehensive conservation plan before artifacts should be permitted to be recovered and treated.26 These principles apply particularly to sunken state vessels and aircraft.27
These rules do not affect the rights of a territorial sovereign to engage in legitimate operations, such as removal of navigational obstructions, prevention of damage to the marine environment, or other actions not prohibited by international law, ordinarily following notice to and in cooperation with the State owning the vessel or aircraft or otherwise entitled to assert the sovereign immunity of the wreck.28
My bold http://www.history.navy.mil/branches/org12-7j.htm
