HMNZS Tui (1970)

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Career (United States (USN)) United States
Name: USNS Charles H. Davis
Namesake: Charles Henry Davis[citation needed]
Builder: Christy Corp, Wisconsin
Laid down: 15 June 1961
Launched: 30 June 1962
Commissioned: 25 January 1963
Fate: Transferred to RNZN
Career (New Zealand (RNZN)) RNZN Ensign
Name: HMNZS Tui
Namesake: The Tui bird
Commissioned: 11 September 1970
Decommissioned: 1997
Fate: Sunk as dive wreck, 1999
General characteristics
Class and type: Conrad class oceanographic ship
Displacement: 1,200 tons standard
1,380 tons full load
Length: 63.7/58.4 m (208.9/191.5 ft)[clarification needed]
Beam: 11.4 metres (37 ft)
Draught: 4.7 metres (15 ft)
Propulsion: 1-shaft diesel electric, 10,000 bhp (7400 kW)
one 620 hp (420kW = 6.5 kts) gas engine housed in the funnel for quiet running during sound experiments
175 hp bow thruster
Speed: 13.5 knots (25.0 km/h)
Complement: (NZ) 36 plus up to 10 scientists
Armament: Unarmed

HMNZS Tui, formerly USNS Charles H. Davis (T-AGOR-5), was one of nine Conrad class oceanographic ships built for the United States Navy (USN), that later saw service in the Royal New Zealand Navy (RNZN). Serving with the USN from 1963 to 1970, these ships were designed to perform acoustic experiments on sound transmission underwater, and for gravity, magnetism and deep-ocean floor studies.

The ship was recommissioned into the RNZN in late 1970, and as HMNZS Tui served as an oceanographic survey and research ship until her decommissioning in 1997. In 1999, the ship was scuttled as a dive wreck


The ship was laid down by Christy Corp, Wisconsin on 15 June 1961. She was launced on 30 June 1962, and was commissioned into the USN on 25 January 1963. The ship was named after Rear Admiral Charles Henry Davis.[citation needed]

Operational history



In 1970, she was transferred to the RNZN, and was commissioned on 11 September 1970 as HMNZS Tui. Tui was named after the Tui bird, and was the second of two ships with this name to serve in the RNZN.

After a partial refit and the installation and testing of scientific equipment, Tui began a program of work for the Defence Scientific Establishment in Auckland. For years Tui went unobtrusively about the kind of work she was designed for, primarily underwater acoustics.

Tui worked in Australian, Indian Ocean and South Pacific waters. She worked on Auckland University research, with DSIR scientists, and with other oceanographic ships. Tui also took part in several American research programs. Her acoustic research was mainly to do with the detection and tracking of submarines.

During the 1970s she made an extensive search for the Maria Theresa Reef.

Decommissioning and fate

In 1997, Tui was decommissioned and was replaced by the hydrographic ship HMNZS Resolution.

In February 1999, Tui was deliberately scuttled 2 kilometres (1.2 mi) from Tutukaka Heads to serve as a tourist attraction and wreck for divers, following a period of work on her which removed any objects in danger of breaking free and welding shut any areas that may have posed a hazard for wreck divers.[1] Her anchor was presented to the City of Napier.[2]

See also


  1. Dive Waikato / Tui retrieved on 9 January 2008
  2. HMNZS Tui Anchor


  • McDougall, R J (1989) New Zealand Naval Vessels. Page 115-116. Government Printing Office. ISBN 9780477013994

External links