HMNZS Waipu was one of eight steel New Zealand-built Castle-class ships built and commissioned by the Royal New Zealand Navy during World War II.

The vessel was ordered after the New Zealand government, facing a requirement for more minesweepers to operate in home waters, chose the Castle-class design because it was simple enough to be built with the country's limited ship construction facilities at the time.

[3][4] In December 1944, she pulled a United States Army oil barge off Ripiro Beach, 32 km (20 mi) north of Kaipara Heads.

With the United States Army tug, Culverden, towing it to Auckland for repairs, arriving two days later.

[2] In 1954, she was sold to Red Funnel Trawlers Pty Ltd. and began trawling from Sydney in 1955, being laid up in 1958.