A Government-backed scheme to harvest minerals from the Pacific seabed could inject £40 billion into the UK economy.
The project run by UK Seabed Resources, a subsidiary of aerospace and defence organisation Lockheed Martin, would see a 58,000 square kilometre region between Hawaii and Mexico farmed for mineral-rich nodules.
The Prime Minister, speaking at the launch of the venture at the Excel centre in east London yesterday, said it was "an enormous scientific opportunity".
"The UK is leading the way in this exciting new industry which has the potential to create specialist and supply chain jobs across the country and is expected to be worth up to £40 billion to the UK economy over the next 30 years," he said.
UK Seabed Resources, in partnership with the Department for Business Innovation and Skills, has now received a licence and contract to explore the seabed, a move Mr Cameron described as "excellent news for British companies and British scientists".
"This seems to me the start of something big and something the Government wants to be involved in," he added.
The tennis ball-sized polymetallic nodules are found "12-and-a-half Shards deep" under the surface of the ocean, according to universities and science minister David Willetts, referring to the height of the new London landmark.
They could provide millions of tonnes of metals including nickel, copper and cobalt to industries.
Mr Willetts described the venture as "an extraordinary opportunity for underwater mining for these valuable and important minerals" and said it could lead to a better understanding of deep sea biology.
It could lead to the UK attracting investments of between £1 billion and £2 billion a year, as well as the creation of jobs in Newcastle, Aberdeen, Portsmouth, Plymouth and Bristol, he added.
The initiative will "give us the opportunity to help set the highest environmental standards and comply with them", Mr Willetts said, stressing that the environmental goal was to make sure any disruption or slurry from the work did not reach layers of the ocean inhabited by marine life.
"The International Seabed Authority and the UK Government will be ensuring there are the highest environmental standards," he added.
Stephen Ball, chief executive of Lockheed Martin UK and UK Seabed Resources, said seabed harvesting was environmentally sound.
"Environmentally responsible collection of polymetallic nodules presents a complex engineering challenge, but our team has the knowledge and experience necessary to help position the UK at the forefront of this emerging industry," he added.
The nodules will be brought to the surface using a combination of underwater vehicles, pumps and suction pipes.