She was named for John Nathan Cobb and was the oldest commissioned ship in the NOAA fleet when she was decommissioned, having previously served in the United States Department of the Interior′s Fish and Wildlife Service from 1950 to 1956 and in the United States Fish and Wildlife Service′s Bureau of Commercial Fisheries from 1956 to 1970 as US FWS John N. Cobb (FWS 1601).

Assigned Seattle, Washington, as her home port, John N. Cobb made her first cruise in March and April 1950, operating off Alaska in search of commercially useful populations of shellfish, especially shrimp.

[1] In 1953, John N. Cobb cruised off the Aleutian Islands, conducting a preliminary search for salmon populations and developing fishing techniques that would allow the successful use of gill nets in the open ocean.

[1] In 1955, she tagged petrale sole in the Esteban Deep – a submarine canyon – in the Pacific Ocean off the west coast of Vancouver Island, British Columbia, Canada.

[1] In 1959, John N. Cobb was supporting the USFWS's Exploratory Fishing and Gear Research (EF&GR) element in 1959 when it fielded its first scuba diving team,[1] which operated from her.

In 1960, John N. Cobb experimented with the use of a high-resolution echo sounder to locate dragging areas off Washington that contained commercial quantities of fish.

[1] In the mid-1990s, John N. Cobb came to the assistance of the purse-seiner Karen Rae, which was in distress in Icy Strait[1] in the Alexander Archipelago in southeastern Alaska.

[1] As fisheries science renewed its focus on the marine ecology of juvenile salmon and other epipelagic fishes, John N. Cobb helped to pioneer the use of surface rope trawls from 1997 to 2007.

[2] NOAA's plans called for John N. Cobb to remain active until August 2008, but the main crankshaft in her original 1931 Fairbanks-Morse locomotive engine broke in June 2008, rendering her inoperable.

She was listed on the National Register of Historic Places on 11 February 2009,[4] but the Academy never repaired her broken crankshaft,[3] and she remained moored in Salmon Bay under the Ballard Bridge for about seven years.

[3] On 26 April 2017, Ron Sloan purchased John N. Cobb, and he contracted with the fishing vessel Sunnford to tow her from Seattle to Winchester Bay, Oregon, where she arrived on 18 August 2017.

[5] As of 2017, John N. Cobb was undergoing repair[5] for commercial use in tuna fishing and for charter for fisheries research and other activities during the off-season.