Norwegian billionaire Kjell Inge Rokke's new research ship is costing $350m, part of his $500m pledge to help the world's oceans.

The 16,000-gt Research Expedition Vessel (REV) will be the largest such ship ever built, more than twice the length of most others.

It is engineered to endure polar ice, harsh weather, and around-the-world voyages from 2021.

Its full capabilities were revealed for the first time last week at a meeting on deep-sea exploration at The Royal Society in London, Science magazine reported.