In Indiana Jones and the Raiders of the Lost Ark, Number One was a Nazi naval officer. He served aboard the Wurrfler, a U-boat commanded by Oskar Schomburg, in 1936, when it was used to intercept the Bantu Wind after it left Egypt with the Ark of the Covenant.
Number One, as Captain Schomburg referred to him, stayed aboard the submarine and was not involved in the apprehension of the Ark or Marion Ravenwood, leaving that task to Colonel Dietrich and René Belloq. As Belloq came back aboard with Ravenwood, he plotted the vessel's course on the navigational maps. Later, he received word that the ship was ready from one of his officers, and set sail. After the submarine dove below the surface and headed toward Geheimhaven, he looked through the periscope before allowing his taller officer to do the same, unaware that a stowaway had tied himself to the periscope.
Behind the scenes
The role of the Wurrfler navigator is not credited in Raiders of the Lost Ark.