Down it drops, slicing through the glistening skin at the surface of the sea. Down further, through dimming shafts of refracted sunlight. Through stiff migratory currents descending into pressure intense enough to crush the life out of any human. Finally, at 2,896 metres (9,500 feet) below the surface, the anchor settles onto the seabed.
This is the journey of a mooring line attached to a buoy floating in Shell's new Stones oil and gas field in the Gulf of Mexico. The buoy is anchored by a three-kilometre line that is already dotted with instruments that collect marine data.
But soon more will be added, because Shell plans to share parts of the line with universities and research institutions.
This partnership will shed new light on deep waters in the Gulf of Mexico where little is currently known. "Exploring the ocean at these depths is today's scientific expedition," says Shell oceanographer Dr Ruth Perry. "Just like early sailors who sought distant continents, we don't know what we'll find. But it's important. If we pool our resources and share our knowledge, we can get there."
Shell uses only a small part of the line to monitor areas where it extracts oil. Underwater sensors already measure the speed, direction and temperature of water currents. But making extra space available to scientists will provide a deeper insight into the ocean's various zones, each of which are home to numerous organisms adapted to their own unique ecosystem.
For now Shell will work with local academic and research organisations through existing partnerships. These groups will have to provide their own instruments and will be able to check data or add new technology every six months when the line is hauled in for maintenance.