Dertigers: De Kerstfilm

Chris Lemons (Finn Cole), Duncan Allcock (Woody Harrelson), and David Yuasa (Simu Liu) are members of a team of saturation divers who work to maintain undersea gas lines in the North Sea. While on rotation, the divers live on-board a vessel in pressurized chambers which maintain conditions required for diving and working at 300 feet (90 m) below sea level. The divers are transported to and from these chambers by a pressurized diving bell, which is lowered to depth from the ship and allows the divers to remain at pressure for the entirety of their four-week work rotation. During a deployment, Lemons and Yuasa exit the bell to begin work on an undersea gas line manifold, while Allcock remains stationed in the bell to monitor their status and attend to the umbilical lines that supply them with communications, hot water and breathing gas. Lemons and Yuasa navigate to the manifold and prepare to begin their work, but on the surface in heavy seas, their vessel's Dynamic Positioning System (DPS) experiences a malfunction, causing the ship to begin drifting away from the work site. The bell is dragged along with Allcock still inside, and Lemons and Yuasa scramble to climb to the top of the manifold so that they will be unobstructed when they are also pulled along. Yuasa successfully ascends the manifold, but Lemons' umbilical line becomes entangled in the structure. Yuasa, realizing that Lemons' umbilical will snap within moments, tells Lemons to switch to his backup air supply, which will provide him with 10 minutes of emergency oxygen. He promises to come back for Lemons, but tells him he must be on top of the manifold for Yuasa to be able to locate him. Moments later, the umbilical snaps, leaving Lemons behind with only his emergency air supply and no means of communicating. Yuasa is carried away on the diving platform still attached to the bell and the ship. Meanwhile, on the ship's bridge, the crew look for solutions to the DPS's malfunction. They are unable to drop anchor due to their proximity to various gas lines: severing one would create an environmental catastrophe. With no other options, the captain and the first mate decide to manually operate the ship's thrusters, preventing them from drifting even further away from the work site while a third crew member works to bypass the reboot process for the DPS. Yuasa makes it back to the bell and regroups with Allcock. On the bridge, another crew-member using an ROV is able to locate Lemons. He is able to observe that Lemons is still alive, but has fallen unconscious and is showing symptoms of oxygen deprivation. He attempts to rescue Lemons with the ROV, but is unable to lift him as Lemons had fastened himself to the manifold to avoid being swept away by the undersea currents. The crew are able to reboot the DPS and reposition over the work site. Yuasa is able to redeploy from the bell and rescue Lemons, whose oxygen ran out 29 minutes prior. Allcock brings Lemons aboard the bell and performs mouth-to-mouth resuscitation, after which Lemons begins breathing again. Yuasa reenters the bell, and he and Allcock both attempt to communicate with an unresponsive Lemons, who appears to have suffered severe brain damage as a result of prolonged oxygen deprivation. Just as the two divers begin to accept that they were too late, Lemons begins to speak and respond normally. The rotation is aborted and Lemons recuperates in the saturation chamber during the voyage home. Back at port, he parts ways with Allcock and Yuasa before journeying home and reuniting with his fiancée Morag (Bobby Rainsbury), revealing to her what happened. In an epilogue, the audience is told that Lemons suffered no lasting mental or physical impairment as a result of the incident, with experts unable to explain the reasons for his survival. Lemons, Yuasa, and Allcock returned to work three weeks later to finish the job they started.