During Voyager's maiden voyage to the Badlands to locate the Maquis raider Val Jean, Cavit manned the bridge tactical station alongside Ensign Rollins, in Lieutenant Tuvok's absence, as he was undercover in the Maquis. Cavit also had to interact with Tom Paris for the mission, who was brought on board Voyager to act as a mission observer. Cavit, like several other officers, immediately displayed contempt for him, believing his criminal past did not afford him the right to be on board. Cavit readied Voyager and coordinated its departure from Deep Space 9 to head to the Badlands. There, it was hit by a massive displacement wave, later found to have been generated by the Caretaker's array. As a result of the impact, Cavit was killed instantly and Voyager became stranded in the Delta Quadrant.
Cavit was played by actor Scott Jaeck who, despite having dialogue, received no screen credit for this appearance.
He filmed his scenes on Tuesday 6 September 1994, Wednesday 7 September 1994, Friday 9 September 1994, Thursday 22 September 1994, and Friday 23 September 1994 on Paramount Stage 8. His work from the second and third day had to be re-filmed due to the replacement of Genevieve Bujold. This took place on Monday 17 October 1994 on Paramount Stage 8. He also filmed an additional day on 2nd unit on Wednesday 9 November 1994 on Paramount Stage 8 and some bridge re-shoots on Friday 18 November 1994 on Paramount Stage 8 and is listed as "Cavit" on all call sheets.
The novelization of Caretaker states that in the year 2358 he served on the USS Kingston, a Federation colony-relief transport, during which time his commanding officer was killed by the Orions. It also notes that, during the events of the episode, Captain Janeway makes a mental note to speak to him regarding his attitude towards Paris on the basis that he is a Starfleet officer and needs to act more professional.
Cavit also appears in the The Brave and the Bold, Book Two novella "The Third Artifact", which gives his first name as "Aaron". The story recounts the Voyager's shakedown cruise in the year 2371. Cavit is revealed to have had a romantic relationship with USS Hood first officer Dina Voyskunsky before an acrimonious breakup in 2359. When the Hood comes to the Voyager's assistance following a series of system malfunctions, the two of them agree to get together at the conclusion of their current missions. Unfortunately, due to the events of "Caretaker", this never happens.
The Autobiography of Kathryn Janeway mentions Cavit, giving his first name as "John".
In an alternate timeline featured in the Star Trek: Myriad Universes novella A Gutted World, Voyager was never stranded in the Delta Quadrant and Cavit served as its first officer until it was destroyed by the Cardassians in 2373.
His name was spelled "Cavitt" in the short story The Ones Left Behind.