Tusker switched on his dive torch and tucked it under the shoulder strap of his harness, aiming it at the back of Sam’s tanks. The light was little use. The hardware was under the water surface. He’d have to do it by feel. First he twisted shut the tank valves and disconnected the regulators, letting them hang loose. Then he reached down between the tanks and found the end of the threaded rod. The wing nut was on the inside of the harness, under a pad at Sam’s back.

“You’re going to have to remove your harness for a bit,” he said. “It’ll be easier to disassemble it if it’s floating in front of me.” Sam wriggled out of the shoulder straps and the harness flopped over like a turtle and floated. “Be sure to stay close to me,” Tusker told her. “In the dark especially, we don’t want to get separated.” Her thicker wetsuit’s buoyancy allowed her to float easily, and she held on lightly to Tusker’s own tanks while he worked.

After a few minutes, he had the wing nuts off and the tanks fell immediately away, disappearing quickly into the depths. The buoyancy wing popped up out of the water like a pool toy, unencumbered by the unwieldy cylinders. Sam slipped back into it, then helped Tusker remove his gear. His thinner suit didn’t offer as much buoyancy on its own, and he struggled to keep his face and arms above the surface while he fiddled with his tanks. Finally, his tanks dropped into the abyss and he cinched on his own harness and wing, panting from the exertion of the awkward work.

“Small triumphs,” he said to Sam.

“Thathi won’t be happy we lost his tanks,” she joked. “I think you’ve lost your security deposit.”

“It’s no use tiring ourselves out trying to swim right now,” Tusker said. “We’ve got about eleven hours until any daylight and I’ve no idea where we are in relation to shore.”

Sam switched on her torch and aimed it at her arm. She had an old square wrist compass lashed over her wetsuit sleeve with a long yellow nylon strap.

“Well, due west is…” she pivoted in the water, “that way.” She held her arm out, which Tusker could barely make out. “So assuming the current was roughly to the south while we were decompressing, the coast should be over there.”

“The question is, how far,” Tusker said glumly. “The Vampire was already about eight miles offshore.”

“Our best hope is the fishing fleet, come morning,” she replied. “Let’s save our torch batteries and if we hear a boat, we can raise our marker buoys and shine our lights on them. Hope someone’s paying attention.”