The ship was on the 1965 Shipyard Norfolk Shipbuilding and Drydock (NORSHIPCO) in Norfolk , Virginia , built. The keel was laid on July 15, the launch on November 15, 1965. The ship was in use from December 1966 to May 2003 in the Pacific along the US west coast. Initially it was used for hydrographic research, later in the field of research on marine mammals .
The ship was named after William Pope McArthur, a US naval officer and hydrograph.
NOAA decommissioned the ship on May 20, 2003. In 2006 it was acquired by Stabbert MaritimeE Yacht & Ship ( Blackwater Worldwide ) and, after being converted into a training and emergency ship, put into service in September 2007. The crew consisted of 45 members, 35 of whom were armed security forces. There were two Hughes OH-6 helicopters on board and three RHIB rigid inflatable boats were carried. Blackwater Worldwide described the McArthur in 2008 as a multi-purpose vessel for military operations, training, peacekeeping and stabilizing operations that can be used worldwide. From 2008, the ship was kept ready and offered as an escort ship to protect against attacks by pirates off the coast of Somalia and was stationed in the Gulf of Aden . However, it was too slow to keep up with modern merchant ships.
At the beginning of 2010 the ship was offered for sale by the company now trading as Xe Services and renamed Eaton by the new owner Afloat Leasing Limited in June 2010 . later sold to the United Arab Emirates- based company Danat al Earat Commercial / Infinity Services FZE, which operates the ship as Maandeeq under the flag of the Comoros .