The set Cape Brett Lighthouse became operational in early in the Second World War and remained as a RDF station until September 1945. The sets were meant to ‘watch strategic waterways for any unseen movement.
RDF (radio direction finding or ‘radar’) was used by all three services during the Second World War. Half the equipment fitted was of New Zealand manufacture at the DSIR. By 1942, radar stations had evolved from a few coastal sites to a network of early-warning and fire-control systems. Test sites were constructed and the technology experimented with supported by an eager government. By 1941 the Radio Development Laboratory was in operation to supply the equipment required.
The Navy’s CW RDF sets were not designed to assist the coastal defence guns hit a target at sea or in the air. The sets were meant to ‘watch strategic waterways for any unseen movement.’ The set for Cape Brett Lighthouse became operational in early in the Second World War and remained as a RDF station until September 1945. The first early-warning set developed for coastwatching was known a Model CW or CWS. The station reported to Naval Officer in Command Auckland for operational and administrative matters to be replaced by Auckland Combined HQ.
Details of the Station
Location: Cape Brett – lighthouse on east coast of North Island
Site of radar: CW MkII ASL (above sea level) 750ft [229m]
ME-1 ASL 260ft [79m] – microwave set built in NZ – smaller aerial and double the range of the CW MkII – this was one of seven installed in coastal posts.
In Service: March 1942 to 1945
Set type: CW (Coastwatching) MkII – installed March 1942 and upgraded later in 1942
ME-1 installed May 1943
In this case the Lighthouse buildings had additional wooden buildings constructed for the RDF set and power house. Power was supplied by two or three diesel generators one of which ran the RDF set. By 1944 those coastwatching stations still in operation were returned to the Army from Navy command by September 1944.
Cape Brett lighthouse was also used to mark a swept channel SCM11 for shipping. It was opened in October 1940 and only channel maintained for access to Auckland from 1941-1942 –points included 2.0nm 47° and 10nm 40° from the lighthouse. On 31 December 1942 B Section 68 battery fired on a launch going from Kerikeri Inlet to Cape Brett. Cost £7-4 not recovered from owner of launch. Patrol launches covered the sea around Cape Brett. In 1941 the patrol launches were organised into a flotilla of three divisions. the first subdivision based at Russell patrolled two miles apart in Area I Cape Brett 90° 5 miles to Poor Knights Is 000° I mile. The craft were the launches Amakura and Te Rauparaha.
After the raider Orion laid mines in 1940 the Navy secretary introduced policy on minesweeping. Routine sweeps would cover a series of designated areas – Cape Brett was one such area for ongoing sweeping. On 6 September 1943 HDML 1186 made an ASDIC contact off Cape Brett and deployed depth charges. In January 1945 the German U-862 was making its way down the east coast of the North Island when the diary of the executive officer noted that the ‘Cape Brett light is a good and continuing navigational aid.’ The U-boat heard and spotted a merchant ship but it got away near to the Cape.
 Peter Cooke, Defending New Zealand: Ramparts on the Sea, 1840-1950s Part 2, Wellington: Defence of New Zealand Study Group, 2000, p. 663.
 ibid., p. 664.
 ibid., 658.
Peter Cooke, Defending New Zealand: Ramparts on the Sea, 1840-1950s Part 2, Wellington: Defence of New Zealand Study Group, 2000, pp. 667, 669.
 Peter Cooke, Defending New Zealand: Ramparts on the Sea, 1840-1950s Part 1, Wellington: Defence of New Zealand Study Group, 2000, p. 375.
 ibid., p. 383.
 ibid., p. 403.
 ibid., p. 410.
 ibid., p. 424
 ibid., p. 427