Polymetallic nodules found on the deep seafloor (>4000 m water depth) have been recognized as an alternative source for certain metals, when land deposits get exhausted. Spread over millions of square kilometres on the seafloor of all the oceans, these deposits contain as much as 40% of combined metals (Mn + Fe + Cu + Ni + Co) and are generally found in the international waters (beyond the exclusive economic zone of any country). India is one of the eight