Skydivers were fictional futuristic submarines featured in Gerry Anderson's TV series UFO, operated by the secretive SHADO organisation as part of Earth's defences against alien aggressors. Like many Anderson vehicles, Skydiver One was designed by Derek Meddings. It could be distinguished from a conventional submarine by its prominent conning tower and by the supersonic twin-engined interceptor fighter that replaced the bow section. An unspecified number of Skydivers patrolled Earth's oceans. Each Skydiver was numbered and the composite sections were referred to as Sky or Diver One, Two, Three etc. Skydiver One was most frequently seen in the course of the series, and if a generic reference was made to 'Skydiver' then this was the one that tended to be referred to. However, the ill-fated Skydiver Three was seen briefly in the episode "The Psychobombs", and in the same episode references were made to Sky 4.
Operation
When a UFO penetrated SHADO's defences and reached Earth's atmosphere, the nearest Skydiver would be alerted. The Sky pilot would enter his craft by a hatch in the rear of the fighter and be fed by an unseen hydraulic system into the cockpit. The submarine would tilt up to an angle of about 45 degrees and the fighter would blast off into the atmosphere to intercept the intruder.. No footage exists of the redocking of Sky and Diver. It can be assumed that the Sky fighter would splash down in the sea and await pickup. The Sky fighters could also touch down on land, though again this was never seen, and it is not sure that they have got any landing wheels.
Propulsion
Skydiver was propelled by twin nuclear turbines, one mounted either side of the hull. There was no external evidence of propellers, so the vessel presumably used some form of magnetohydrodynamic drive or pump-jet. The submarine was also capable of extremely rapid surface travel in 'seaskim' mode. This appears to be some form of hydrofoil or hovercraft-type travel, which to judge by the accompanying sounds uses jet or rocket propulsion. Seaskim may have been designed as a method of overcoming the loss of streamlining caused by the absence of the fighter, which would have reduced Skydiver’s speed underwater. "Close Up" showed that Skydiver could go from seaskim to an emergency crash dive in a matter of seconds.
Crew
Skydiver typically had a crew of five or six, of whom the captain was also usually the Sky pilot. The captain’s cabin was directly aft of the main control section. Quarters for the rest of the crew were never seen, and given the size of the submarine – not much longer than a WW2 U-boat, and a third of that taken up with the aircraft section – they could not have been large. It is possible the crew were periodically relieved before they needed somewhere to sleep. Skydiver 1 is known to have had two captains in the course of the series, Peter Carlin and Lew Waterman. The latter was formerly the astronaut pilot of a lunar interceptor craft; his career is a testament to the flexible employment policies practiced by SHADO. Presumably Carlin was reassigned, but his fate is unrevealed. Personnel from other SHADO divisions were also seen serving aboard Skydiver One on occasion. Paul Foster spent several months with Waterman's crew, becoming close friends with the captain, as part of his training to become a SHADO operative. Nina Barry, normally a Moonbase operative, briefly served as communications officer. SHADO Commander Ed Straker also travelled aboard Skydiver One from time to time, despite his near-crippling claustrophobia.
Bases
Only Skydiver Three was ever seen docked at a base, which was in a cavern connected to the sea by a tunnel. It can be assumed other Skydivers were serviced similarly, or else resupplied at sea.
Weapons
The Sky fighters were armed with four machine gun cannons, two on either side of the cockpit, and a pod containing missiles mounted under each wing. An unusual design feature of these is that the rear ends of these pods were clearly the fighter’s jet exhausts, though the air intake was mounted beneath the fuselage. As seen in "Sub-Smash", the Diver section was also armed with torpedoes. They were presumably kept behind concealed hatches, as it is difficult to tell from a cursory study of the Skydiver exterior where the tubes might be. Only one torpedo was ever seen fired in anger, in a manner strangely reminiscent of stock footage from a conventional submarine.
Emergencies
The SHADO codeword "sub smash" refers to an emergency at sea involving one of the vessels. In the episode "Sub-Smash" Skydiver One is unable to surface after a UFO attack and sinks to the bottom of the sea. Sky 1 is barely able to launch, allowing Captain Waterman to notify SHADO of the vessel's location, but several crewmembers, including SHADO Commander Ed Straker, Paul Foster, and Nina Barry, are trapped below the surface. The episode reveals that emergency evacuation can be accomplished through the docking hatch, although only one or two crewmembers can use it at a time and the hatch must be cleared of water each time ; use of this exit is also dependent upon the amount of battery power remaining with which to operate the pumps. An alternate, more dangerous egress route is via the torpedo tube, although in the "Sub-Smash" incident this exit malfunctions and fails to open.
