Like most sea-going ships, they could be sent to the scrapheap, their bodies cannibalised for valuable metal that can be melted down and reused. But disposing of them is a dirty, dangerous and poorly paid business for those who undertake this work in some of the most deprived parts of the world.

There are some, however, who believe that these dirty monoliths of the oil age can instead be rehabilitated – they want to transform them into sources of clean, renewable energy. Engineers believe it is possible to use the vast hull of oil tankers to create floating power stations that can convert the ocean swell into electricity. This is the ambitious plan to create the world’s first “waveships”.

“The current problem with most wave energy projects is that they are fixed in place, close to the shore so they can be connected to the electricity grid,” says Andrew Deaner, managing director of ShipEco Marine, the company behind the waveship project. “This isn’t necessarily where the best waves are. With a ship you are mobile, so you can move to the edge of low-pressure weather systems where the waves are bigger and there is more energy.”

Transforming a supertanker into an environmentally friendly mobile power station draws on other areas of the oil industry for its inspiration. Growing up, Deaner spent a great deal of time on diving support vessels built by his father for installing and repairing oil wells and pipelines on the sea bed. These vessels have special chambers cut through their hulls, known as moon pools, which allow divers and submersible vehicles to be lowered safely into the ocean.