Experiences of British, U.S., and Allied forces early in World War II underscored the need for effective close-in fire support and beach bombardment. The most effective method for providing this much-needed capability was not to develop specialized platforms for the task, but to modify the ships and craft that already had the capability to get close-in to shore in medias res. The answer was landing craft.
Much as the Soviets had done with their Katyusha on land, the British Royal Navy and U.S. Navy began modifying their existing and planned landing craft and boat designs to accommodate rapidly evolving rocket and rocket-launching technology. By the war's end, a number of different craft had been modified to carry and launch rockets for close-in fire support.