A search for a candidate ship, capable of being modified for an inboard center well, led to selection of Mizar in late 1963.

[5] In 1964 Mizar's successful search for the sunken submarine, before modification for the desired center well, further demonstrated the need for a sheltered work space with heavy lift and towing capability.

[5][6] NRL's previous vessel with a center well, USS Hunting, provided experience and some problems to avoid in the Mizar design.

A flush mounted, water tight hydraulic door of two parts, one fore and one aft, closed the well at the main deck level.

Large "breather" ducts from the well relieved air pressure caused by wave action within when the doors were closed.

[8] On April 15, 1964 Mizar was reclassified AGOR-11, designed for deep oceanographic search and research, and to be operated by MSTS for NRL.

The ship was fitted with a deepsea vehicle (fish), equipped with strobe lights, cameras, sonar, and magnetometer.

Her major tasks were to be ocean floor study and service as a floating base for underwater acoustic, chemical, and biological research.

[13] As an example of extensive acoustic research with general oceanographic observations included was the ship's work in Operation NORLANT, an acoustic propagation and noise experiment that involved aircraft as well as NRL ships Mizar and Hayes and the Norwegian research vessel Sverdrup in the Greenland, Norwegian and Barents seas.

[26] Mizar was withdrawn from active service entering the James River National Defense Reserve Fleet on December 17, 1989.

[27] Bay Bridge Enterprises, LLC of Chesapeake, Virginia was awarded a $243,900 contract for the dismantling and recycling of Mizar on 21 July 2005.