The Atlantic 21 is part of the B class of lifeboats that served the shores of the United Kingdom and Ireland as part of the Royal National Lifeboat Institution (RNLI) inshore fleet. The Atlantic 21 was the first generation rigid inflatable boat (RIB), originated at and by Atlantic College in South Wales, the birth place of the RIB after which the craft is so named. The school was also one of nine locations where the RNLI first established lifeboat stations using smaller inshore watercraft. Atlantic College Lifeboat Station was commissioned by the RNLI in 1963 and decommissioned in 2013.