Troops involved in Operation Overlord, including members of the 4th Division scheduled to land at Utah, left their barracks in the second half of May and proceeded to their coastal marshalling points. To preserve secrecy, the invasion troops were as much as possible kept out of contact with the outside world. The men began to embark onto their transports on June 1, and the 865 ships of Force U (the naval group assigned to Utah) began their journey from Plymouth on June 3 and 4. A 24-hour postponement of the invasion necessitated by bad weather meant that one convoy, U-2A, had to be recalled and hastily refuelled at Portland. The ships met at a rendezvous point (nicknamed "Piccadilly Circus") southeast of the Isle of Wight to assemble into convoys to cross the Channel. Minesweepers began clearing lanes on the evening of June 5.