On the 24th, "Arikara" moved to Lee-on-the-Solent to join the British tug fleet in preparing for the invasion of Europe. During the remainder of April and all of May, she towed to dispersal points on the southeastern coast of England portions of the two "mulberries," artificial harbors to be erected on the French coast after the initial assault to provide logistical support for the movement of all Allied armies inland. On 15 May 1944, she was reclassified a fleet tug and redesignated ATF-98. Throughout the period leading up to the invasion, "Arikara" helped to repel German air attacks; and, though near misses shook her considerably, she suffered neither hits nor significant damage from shell fragments.