Petey Giraldi was a crewman aboard the USS Bluefin.
Petey is complaining to another sailor about how he enlisted to sink German ships and not go in the other direction on a secret missions for "some broad." The sailor tells Petey not to worry and to get some rest. Unbeknownst to Petey, Dean has been hiding under a bunk and as Petey is reading Dean tosses a quarter out. Petey picks it up and is confused to see that it is from 1996. Dean then quickly jumps Petey and puts him in a headlock, asking him where he can find Delphine Seydoux. Dean then takes Petey's clothes and hogties him in the bathroom as he goes to find Delphine.
Just as soon as Dean finds Delphine, Petey is found and along with the galley cook, Harris, race to the war room and alert the Captain Deerborn of what had happened. Dean explains he is on a mission from the future, to the disbelief of Captain Deerborn, who orders Petey to keep watch on Dean till the ship hits shore. As Dean and Delphine talk about his mission, Petey attempts to test Dean asking him about future events, trying to get a handle on his story that the submarine is going to sink. While Delphine goes to clear the warding sigils on the sub, Prtey asks Dean if the Allies will win the war. Dean tells him 1945, and asks if he believes him, which Petey simply replies that he "reads a lot of Flash Gordon."
As the submarine is being pursued by a German destroyer, Delphine returns and tells Dean he needs to kill her to get rid of the final sigil. As Petey looks on, the submarine is hit with a depth charge before Dean goes through with it. The three then get called to the operations room, where Delphine decides to use the Hand of God to destroy the German ship. Killing herself, Petey and the rest of the crew in the process.