Contrary to early hopes that seabed mining would generate extensive revenues for both the exploiting countries and the Authority, no technology has yet been developed for gathering deep-sea minerals at costs that can compete with land-based mines. Until recently, the consensus has been that economic mining of the ocean depths might be decades away. Moreover, the United States, with some of the most advanced ocean technology in the world, has not yet ratified the Law of the Sea Convention and is thus not a member of the Authority.