Under an agreement made between the Commandant and the Chief of Naval Operations, the Coast Guard supplied officers and crewmen for a number of LSTs, beginning in 1943. Up to that time Coast Guard crews had served successfully on board the larger Navy attack transports (APs & APAs) and with personnel to spare, it was an obvious choice to let the Coast Guard continue to assist in manning the ships of the ever increasing Navy fleet. The Coast Guard's experience with sailing in shallow waters as well as on the high seas made the Coast Guard crews a valuable addition to the Allied invasion fleets and they readily took to all of the various types of landing craft utilized by the Navy, including the vaunted Landing Ship, Tank, or LST.

Even with Coast Guard crews all LSTs remained commissioned US Navy vessels. Most of the "Coast Guard" LSTs had crews made up entirely of Coast Guardsmen but there were exceptions. Some had Navy crewmen on board that manned the smaller landing craft attached to the LSTs or filled rates that the Coast Guard did not have enough men in such as radiomen, and medical staffs were typically Navy. To add to the confusion, other mainly Navy-manned LSTs had some Coast Guardsmen aboard. In at least two instances, Coast Guard crews from LSTs actually "swapped" ships with Navy-manned LSTs during the war. For example, the Coast Guard crew of USS LST-25 "cross-decked" ships with the Navy crew of USS LST-381 in August 1943.

Coast Guard-manned LSTs participated in almost all of the major amphibious invasions undertaken by the U.S. during the war. In total, they completely manned at one time or another 77 LSTs, roughly 8 1/2 percent of all LSTs in service. Of those, they earned 10 1/2 percent of the total battle stars awarded to the LST fleet. Although they were irreverently known by their crews as a Large, Slow Targets, these were the vessels that put troops and supplies on enemy shores, ensuring in the end a victory for the Allies over each of the Axis powers.