Then, in a process thought to span millions of years, they get coated in layers of liquidised metal, eventually becoming solid, lumpy rocks that resemble burnt potatoes.
These formations, known as polymetallic nodules, have caught the attention of international mining companies because of what they harbour: rich deposits of commercially sought-after minerals like cobalt, nickel, copper and manganese — the very metals that go into the batteries for renewable technologies like electric cars, wind turbines and solar panels.
