Ocean MiningThere's a lot of staking around hydrothermal vents and rifts. REE's have been identified in abundance too. The problem is the engineering required to obtain them in any economical way. It's the equivelent of going to the moon. Japanese engineers think this can be overcome in 15 years but they are not sure if the economics wil rival the land method anytime over the next 50 years. We'd be better off exploring space for minerals. BTW there are drive systems being developed to do just that. Robotic exploration of space is only 20 years away. We know there are corbon planets and iron cores out there. Distance is the only problem. Within 50 years we will have a space refinery and IRT drives. Our only obsticle is creating enough power in a small enough space. A lot of work is being done in this respect.