The use of low-cost ROV for deep-sea mineral ore prospecting

Terrestrial mineral resources are getting harder to exploit; most of the ‘easy’ deposits have already been exploited and hence the costs are continuing to rise. The world’s undersea reserves are estimated to include 10 billion tonnes of polymetallic nodules (Figure 1), with an estimated value of metals in the seabed globally rated at over $2 trillion per annum (Lodge 2015)

The only problem is knowing where the valuable resources lie and hence prospecting with Remotely Operated Vehicles (ROVs) is an area of increasing developmental interest (Figure 2). Deep sea mining is not without opposition due to the vastly unexplored nature of the earth's sea floor. The science community especially environmentalists believe that resources needed for independent scientific assessment at those depths are essentially non-existent (Figure 3). Currently most commercially available vehicles (ROV's) in an ‘affordable range’ for small institutions and private individuals, range from ∼£500–£30,000. Typically within this range, with few exceptions, they have a depth capacity of 100 m, which limits them from undertaking deep water operations (300 m+). To go ‘deep’ the price of ROV technology increases exponentially and with a conversely decreasing range of technology providers. With the advent of increasingly powerful and energy efficient microcomputers there exists an opportunity to propagate ‘low cost’ ROV technologies to greater and greater depths for the benefit of mineral and ecological exploration. Accordingly, the University of Bristol is developing prototype low cost Observation Class ROVs for exploration at depths below 300 m, using the 500 m Victory Shaft at Geevor Tin mine near, Cornwall for on-land testing.