Marty is a diminutive-sized pirate with a bald appearance and a thin beard. Like other crew members, he was a distinctive pirate who challenged himself to overcome adversaries.
Marty appears in a motley crew during a plan to get to Isla de Muerta to which when Jack Sparrow points out to the HMS Interceptor, Marty and the motley crew join with Jack as he commandeers the vessel as captain. As the motley crew sails across a dangerous storm, Marty and the motley crew were soaked in the rain as the crew begin doubting on Jack's apparently broken compass and by the following day, the crew looked over the railings watching sharks swim past by as the Interceptor began moving slowly as the motley crew went back to work under Jack's orders. As the Pearl arrives at Isla de Muerta, Jack Sparrow and Will Turner navigate the treasure cavern alone while Marty and the rest of the crew are left behind under Jack's orders to keep the Pirate's Code.
Back on the Interceptor, Will came back on board with Elizabeth Swann, to which Will explains to Marty and the crew that Jack was left at Isla de Muerta. Later, the Black Pearl attacks the Interceptor as Marty joins battle against Captain Barbossa and his pirate crew just as he readies the cannons to prepare for battle. Marty survived, but is later taken prisoner along with the motley crew by the cursed crew. Elizabeth manages to free Marty and the rest of the crew and during the plan to go back to Will and Jack, Marty tells Swann that Jack owes the crew a ship to which the motley crew agreed what Marty said before sending Elizabeth away. Marty and the rest of the crew arrive at Isla de Muerta under command by Joshamee Gibbs and Anamaria with ten new recruits and later rescued Jack during the battle against the Black Pearl, allowing Jack to be captain once more.
With Jack as the captain of the Pearl, Marty comments that Jack was acting strange while looking for the key to Dead Man's Chest. The crew was later captured by the Pelegostos Tribe just as Marty was one of the few victims to escape Pelegostos Island and into the Pearl.
During battle against the Flying Dutchman, Marty informed Jack's crew that the Dutchman is falling for the Pearl and hauled a net of gunpowder to destroy the Kraken, only for it to be enraged. After Jack sacrifices himself to save the crew as Jack ends up in Davy Jones' Locker, Marty survived the battle just as Marty and the crew arrive at Tia Dalma's shack, while the crew plans to bring Jack and the Pearl back from Davy Jones' Locker.
Arriving in Singapore, Marty and the crew fought against an ambush in Singapore. Marty later reunites with Captain Jack Sparrow after escaping from Davy Jones' Locker and later found out that the Kraken was killed by Davy Jones under command by Ian Mercer as he later tells Jack about the presence of the Empress. Later when Jack questioned when anyone came to rescue him, Marty was the first to raise his hand to which he agrees of what Sparrow questioned,
During battle at the maelstrom, Marty used a blunderbuss to fight of the Crew of the Flying Dutchman. After the battle at the maelstrom stops, Marty remains his duty as crew of the Pearl under Barbossa's command.
Marty is one of the pirates who helped Jack steal the bank from the newly opened bank at Saint Martin, alongside Joshamee Gibbs, Scrum, and the crew of the Dying Gull, to which due to Jack only finding a little amount of money, Marty began to lose faith in Sparrow's failure. Fortunately, when Jack Sparrow is sentenced to be killed during sunrise to which Marty and the crew manage to free him and Carina Smyth from execution. Jack leads the crew on a quest to find the Trident of Poseidon under competition by Armando Salazar and the Silent Mary.
In search for the Trident, Jack and his crew could not find the artifact Salazar is looking for on the map. In less than a day, however, the crew notices the crew of the Silent Mary are chasing against Jack in frustration just as the mutiny put Joshamee Gibbs as captain.
Having escaped from the undead crew, Marty and the rest of the crew and escaped via rowboat, Gibbs sees the Black Pearl back in its regular size. Marty joined the crew in fighting against Salazar and his undead crew who later retreated after the Pearl arrived on another island.
Onboard the Pearl, Marty stays onboard while Barbossa, Jack, and Carina try to find the trident. After destroying the trident during battle and Barbossa and Salazar both die during battle (also destroying the curses of the sea), Marty and the rest of the crew mourn for the loss of Barbossa who sacrificed himself to save Jack's crew. Later, Marty joins the crew of the Black Pearl once again with Jack Sparrow in his duty as captain.
- According to Martin Klebba (the actor who played Marty), Marty was originally named "Dirk", but director Gore Verbinski preferred the name "Marty", in reference of the actor's name.