Development of the destroyer escort was promoted by the British need in World War II for anti-submarine ships that could operate in open oceans at speeds of up to 20 knots. The 50th came closer than any other Allied unit to its June 6 objective, as Bayeux was captured by the British the day after the landing. Hedgerows impede Allies' progress in Cherbourg, France: "Too many hedges," an Allied unit reported.