USCGC Mariposa

The USCGC Mariposa (WLB-397) was an Iris-class buoy tender belonging to the United States Coast Guard launched on 14 January 1944 and commissioned on 1 July 1944.

Design
The Iris-class buoy tenders were constructed after the Mesquite-class buoy tenders. Mariposa cost $926,446 to construct and had an overall length of 180 ft. She had a beam of 37 ft and a draft of up to 12 ft at the time of construction, although this was increased to 14 ft in 1966. She initially had a displacement of 935 lt; this was increased to 1026 lt in 1966. She was powered by one electric motor. This was connected up to two Westinghouse generators which were driven by two CooperBessemer GND-8 four-cycle diesel engines. She had a single screw.

The Iris-class buoy tenders had maximum sustained speeds of 13 kn, although this diminished to around 11.9 kn in 1966. For economic and effective operation, they had to initially operate at 8.3 kn, although this increased to 8.5 kn in 1966. The ships had a complement of six officers and seventy-four crew members in 1945; this decreased to two warrants, four officers, and forty-seven men in 1966. They were fitted with a SL1 radar system and QBE-3A sonar system in 1945. Their armament consisted of one 3"/50 caliber gun, two 20 mm/80 guns, two Mousetraps, two depth charge tracks, and four Y-guns in 1945; these were removed in 1966.

Career
Upon receiving her commission Mariposa was assigned to the 3rd Coast Guard District and homeported in Staten Island where she was used for general ATON until the end of World War II. After the end of the war, she stayed in Staten Island. In 1990, she underwent a major renovation and from June 1991, until being decommissioned, she was stationed in Seattle.

In 2000, she was transferred to the U.S. Navy for use as a training hulk.