In the United States, the vessels were known as 44' Motor Lifeboats, "a boat in which her crew always had the confidence that she would bring them safely back to port."
The 44' MLB was designed by the U.S. Coast Guard, with work starting on the prototype (USCG 44300) in April 1961, which was completed on March 9, 1962.
A total of 110, 44' MLB's were built for the U.S. Coast Guard, with the last boat (USCG 44409) being completed in 1972.