Conifer and her sister ships, commonly referred to as "one-eighties", served as the backbone of the Coast Guard's Aids to Navigation fleet for over 50 years before their replacement by the newer Juniper-class cutters.
The tenders were designed to provide logistics support (fuel, fresh water, and food) to staffed off-shore lighthouses.
The SAR requirements provided finer design lines at the bow and stern, and a reduced beam to length ratio.
Single screw propulsion, a cutaway forefoot under the bow, and rounded bilges facilitated ice-breaking.
The contract for the lead ship was awarded to Zenith Dredge Company of Duluth, Minnesota, in January 1941.
The Coast Guard also operates three smaller classes of buoy tenders: WLM's (Coastal), WLI's (Inland), and WLR's (River).
The DC electricity powered a single Westinghouse main-motor, which was coupled directly to the propeller shaft.
Conifer sailed across the Great Lakes and through the St. Lawrence Seaway en route to the Coast Guard Yard in Baltimore, Maryland.
Conifer steamed as far south as Bermuda, east to the Azore Islands off Africa, and north into the icepacks of Greenland.
When threatened with imminent attack from a Canadian B-24 bomber, Conifer's gun crews were prepared to open fire when the aircraft finally responded to radio communications.
Her primary mission was to service aids to navigation along the southern Virginia and northern North Carolina coasts.
She was temporarily decommissioned, and commenced a $7.5 million overhaul under the Service Life Extension Program (SLEP).
Six pieces of original equipment were re-installed: the anchor windlass; the mast; the ship's bell; the helm wheel; the main motor; and the steering gear.
With the exception of minor preventive maintenance and scheduled cleanings, the main motor has worked continuously for 50 years.
The Motor Cargo Boat was powered by a Detroit 3-53, and the rigid hull inflatable features a turbo-charged Volvo Penta engine and out drive.
On 4 October 1986, Conifer was assigned to Commander, Eleventh Coast Guard District, and arrived in San Pedro, California.