1. A British charity is conducting the salvage pursuant to a plan approved by the British government.
2. The British charity hired a U.S. company to do the salvage. The arrangement is basically a contingency fee. If the company finds enough value, it makes a profit. If it finds nothing, it has lost millions. The Brits get cultural artifacts and what of the ship that can be salvaged.
3. I doubt there is a company in the UK that has this kind of highly specialized expertise.
Thanks ct!