Why Britain cannot simply stop Pacific wreck salvage

Why have the Royal Navy and Foreign Office not done more to stop illegal salvage of Pacific warship wrecks?

They are supporting enforcement with a forward patrol presence, but practical action depends on regional sovereignty, budgets, and Britain contributing its own resources.

The Navy and Foreign Office are already using the tools available to them. Royal Navy offshore patrol vessels based around Singapore provide a forward presence that can assist regional enforcement. The larger limitation is sovereignty and resources: Britain cannot simply direct another state to police wreck sites in its own waters. Asking regional governments to spend their budgets protecting British naval history is less effective than contributing ships and personnel directly.