Medea in the Middle

By Theresa Williams

Slackjaw Sally here. I ran into my old friend Medea yesterday. As part of her job, she often hangs out at the same depths as me. Her job is to manage Jason’s tether and keep him isolated from surface motion. Together, she and Jason were designed to help scientists study the deep ocean and seafloor.


Don’t tell her I said so, but Medea weighs a hefty 800 pounds in the water. She uses this weight to absorb movement from above, letting Jason move around on the ocean floor without being affected by ship movement. She has lights, one black and white camera and one color camera to identify terrain and to keep an eye on Jason. You could think of her as Jason’s personal lifeguard... or mother!

Jason is connected to Medea by a 2-centimeter (.84 inch) diameter tether about 35 meters (114 feet) long with a breaking strength of 41,000 pounds. Jason weighs 8,000 pounds on land, but in the water he’s neutrally buoyant like me. He’s propelled by 6 thrusters that can move him in three planes allowing him to be very maneuverable and do his job of detailed survey and sampling tasks. He also has a bank of lights and many cameras to allow the operators on the boat to see what’s at the bottom of the ocean when they move him around and use him to photograph and pick up the rocks they want.

Jason gets all the credit for collecting the samples, but he still needs Medea to keep him safe.

Gotta swim!