 The scene on the speedboat where Lt. Callahan sings "The Ride of the  Valkyries" was not in the script. Director Alan Myerson (qv)  laughed so hard at Leslie Easterbrook (qv)s vocal improvisation  between takes, that not only did Leslie and a cameraman have to grab  Alan to prevent him from falling off the boat, but Alan also decided  to use the opera singing as part of the scene itself.