He was working in the situations room while Hoshi Sato and Travis Mayweather reviewed historical archive photos from the Terra Nova Expedition at the helm station. He was also present when Enterprise arrived at Terra Nova and a landing party was sent down to investigate. Following the attack of the landing party by the Novans, Tanner manned the helm station while Mayweather transported down to the planet. He remained at the helm station until Malcolm Reed was released by the Novans. (ENT: "Terra Nova")
Tanner manned the engineering station on the bridge while an away team was held hostage by the Andorian Imperial Guard at the monastery at P'Jem. When Travis Mayweather left his station to join the discussion between Hoshi Sato and Malcolm Reed in the situation room, Tanner manned the helm station. He later worked on consoles in the situation room when Thy'lek Shran contacts Enterprise NX-01. (ENT: "The Andorian Incident")
He was working in the situation room on the bridge when cargo module 8 of the ECS Fortunate was jettisoned including the away team of Enterprise. He remained on the bridge and was present when Enterprise detected Nausicaan weapons fire and intercepted the Nausicaan ships which attacked the Fortunate. (ENT: "Fortunate Son")
Tanner served as relief helmsman during the absence of Travis Mayweather when Enterprise had to deal with an unidentified species. In the current time he served in the aft section on the bridge and reached Captain Archer a flashlight when the main power went offline. (ENT: "Silent Enemy")
He was also on duty on the aft bridge when the ship made first contact with the Valakians, and visited later the mess hall later, (ENT: "Dear Doctor") and when a group of Vulcans came aboard. (ENT: "Fusion")
He was working in the situation room on the bridge when Enterprise discovered the crash landed Kantare supply ship and sent down an away team. He replaced Ensign Mayweather at the helm station when he was part of the away team. (ENT: "Oasis")
Ensign Tanner served at the helm while Captain Archer and Travis Mayweather were held prisoners by the Tandarans in their Detention Complex 26. He managed to escape two attacking Tandaran patrol ships. (ENT: "Detained")
In early 2152, Lieutenant Reed was hoping to add a third officer assigned full-time to the armory, this would give Tanner the time to begin upgrades to the torpedo launchers. Tanner was later wounded when a mine exploded on the hull of Enterprise and was brought into sickbay by Crewman Rossi. (ENT: "Minefield")
Tanner recovered and served at the helm when communications officer Hoshi Sato tried to talk to the Kreetassans (ENT: "A Night in Sickbay") and when Trip Tucker, T'Pol and Travis Mayweather boarded a Suliban cell ship to rescue Malcolm Reed and Captain Archer from an alien world. (ENT: "The Communicator")
When the crew was forced to live and work at the catwalk for a few days, he manned the temporary helm control at the catwalk command area when Captain Archer requested him to relieve Travis Mayweather from the makeshift after he passed the ship through a maze of plasma eddies. Later he participated in watching another film for movie night. (ENT: "The Catwalk")
Tanner was working on the bridge when Commander Tucker and the Arkonian Zho'Kaan went missing on a moon in Arkonian space (ENT: "Dawn") and when Captain Archer and Ambassador Soval tried to implement peace talks with an Andorian group led by Commander Thy'lek Shran on the planet Weytahn. (ENT: "Cease Fire")
Tanner was on duty on the bridge and manned a station in the situation room when Lieutenant Reed reported the attack of two Xindi-Reptilian warships to Captain Archer (ENT: "Rajiin") and when Archer informed T'Pol about the mission status from the Xindi-Arboreal colony. (ENT: "The Shipment")
Tanner was working in the engine room when the three Orion women D'Nesh, Maras, and Navaar came aboard. Like every male aboard the ship he was also affected by the Orion pheromones and witnessed a dispute between Commander Tucker and Kelby. Later, when Harrad-Sar tried to hijack Enterprise and Captain Archer, Tanner was working on the bridge. (ENT: "Bound")
Tanner's name was mentioned in "Minefield" and "The Catwalk."
He was also featured in the extended deleted scene in sickbay in the episode "Minefield". A distressed uniform worn by English in his performance as Tanner was sold off on the It's A Wrap! sale and auction on eBay. 
- "Broken Bow"
- "Strange New World"
- "Terra Nova"
- "The Andorian Incident"
- "Fortunate Son"
- "Silent Enemy"
- "Dear Doctor"
- "Vox Sola"
- "Two Days and Two Nights"
- "A Night in Sickbay"
- "The Communicator"
- "The Catwalk"
- "Cease Fire"
- "The Breach"
- "The Xindi"
- "The Shipment"
- "Chosen Realm"
- "Storm Front"
- "Storm Front, Part II"
- "Observer Effect"
- "The Aenar"
- "These Are the Voyages..."