Known as the Clarion Clipper Zone of the Eastern Pacific, exploration back in the 1980s found areas of golf ball-sized nuggets rich in copper, nickel, manganese and cobalt on the sea floor at depths starting from 4500 metres, according to Nautilus.

The licences were granted by the International Seabed Authority at its annual meeting in Jamaica this week, and cover an initial period of 15 years.

Nautilus chief executive officer Steve Rogers said the company's Solwara-1 project in the Bismark Sea offshore Papua New Guinea helped Nautilus adapt technologies to access sea floor resources at water depths of 1600m.

"Ultimately we intend to seek to establish the capacity to expand operations to undertake larger scale projects envisaged in the deeper waters of the CCZ," he said.

"Nautilus is pleased to be at the forefront of development, working with industry and the scientific community to establish methodologies and processes to develop these significant resources in ways that are socially and environmentally responsible."

Initial sea floor mining at Solwara is designed to hit a production rate of 1.2 million tonnes per annum of dry ore delivered to Rabaul Port, with a ramp-up option to hit 1.8Mtpa.

First ore is expected 30 months after the project gets the final go-ahead.

The Solwara-1 project hosts an indicated resource of 870,000t with copper of 6.8%, gold at 4.8 grams per tonne and silver at 23gpt.

There is also an inferred resource of 1.3Mt at 7.5% copper, 7.2gpt gold and 37gpt silver.

The copper resources were calculated using a 4% copper cut-off.