This paper model is the Thunderbird 4 (TB2 POD4 Options) submarine, based on British science fiction television show Thunderbirds, the paper model was created by ijoy. A small utility submarine for underwater rescue, Thunderbird 4 is carried aboard Thunderbird 2, nearly always in Pod 4, although it was once transported in Pod 6 ("Attack of the Alligators").
In the episode "Terror in New York City" Gordon launches the craft by emergency procedure, from Thunderbird 2's hangar and sliding along the island runway, with the runway's overhang automatically dropping into the sea as Thunderbird 4 approaches it. However, the submarine's slow speed renders it impractical for Thunderbird 4 to try and travel on its own.
Thunderbird 4 is 9 m long and 3 m wide, and is fitted with an adjustable searchlight which can be raised or lowered to reveal a variety of rescue instruments, such as cutting lasers, electromagnets, demolition rockets and battering rams, which can be extended from the nose section. Thunderbird 4 is piloted by aquanaut Gordon Tracy.