Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Nautilus UK is a British trade union representing shipmasters, officers and cadets serving on merchant ships, as well as other maritime workers such as harbourmasters and marine pilots. The union was formed in 1985 as the National Union of Marine, Aviation and Shipping Transport Officers (NUMAST) by the merger of the Radio and Electronic Officers Union (REOU) and the Mercantile Marine Services Association (MMSA) with the Merchant Navy and Airline Officers Association (MNAOA).