Oceans cover three-quarters of the Earth, yet only 20% of the seafloor has yet been mapped. "There's just no terrestrial equivalent, which is why we so often compare the ocean to the moon or outer space. One downside of success could be that more complete mapping would significantly accelerate the exploitation of the oceans, however. Right now there’s a big push to exploit the deep sea and open the first commercial mines in international waters," said Trethewey. "The ocean is vast, incomprehensibly vast [...] and without money to fund monitoring and enforcement at sea, more rules are largely meaningless."