The big question is what to do with these enormous structures when the fossil fuels stop flowing. With curbing climate change rising up the international agenda, and with some questioning whether we have already passed peak oil, hastened by the coronavirus pandemic, the number of defunct rigs in the ocean is set to get bigger. Removing them from the water is incredibly expensive and labour-intensive. Allowing them to rust and fall into disrepair is an environmental risk that could seriously damage marine ecosystems.

For some species, offshore rigs are even better nurseries than natural reefs. The towering pylons are the perfect spawning grounds for tiny fish larvae
But there is one way in which these old rigs can be remarkably useful: the subsurface rig provides the ideal skeleton for coral reefs. Teeming with fish and other wildlife, scientists say that offshore rigs like Platform Holly are in fact the most bountiful human-made marine habitats in the world.