The Black Swan Project, the search for sunken treasure off the Iberian Peninsula, ended up netting arguably the greatest find on the ocean floors ever: $500 million in silver and gold coins believed to be from the wreck of the Nuestra Senora de las Mercedes.

But the project also has caused it painful litigation for the Tampa, Fla., exploration company, along with regulatory headaches. Lawsuits are not unusual with such treasure troves but, when all is said and done, this litigation has the potential to rewrite maritime law for salvaging in international waters.