14 April 2025 marks a memorable turning point for New Zealand’s marine science community. After more than four decades of steadfast service, the research vessel Kaharoa has been officially retired by the National Institute of Water and Atmospheric Research (NIWA). Her final voyage, carried out alongside her successor Kaharoa II, marked the end of an era in coastal and open-ocean scientific research.
Affectionately dubbed The Little Ship That Can, Kaharoa may not have been the biggest or flashiest vessel in the NIWA fleet, but her contribution to marine science was both vast and significant. Launched in Whangārei in 1981, the 28-metre vessel quickly proved her worth. Designed primarily for coastal surveys, she was nevertheless capable of venturing far beyond the limits of New Zealand’s Exclusive Economic Zone (EEZ). Over her 42 years of service, Kaharoa not only mapped and assessed inshore fish stocks but also travelled more than 75,000 nautical miles across the Indian and Pacific Oceans, deploying thousands of ocean-profiling Argo floats from Cape Town to Santiago.
Her technical specifications reflect her versatility. With a displacement of 300 tonnes, a cruising speed of 10.5 knots, and an endurance of 30 days at sea, Kaharoa was a sturdy and dependable platform for scientific exploration. Equipped with a Hiab sea crane, a heavy-duty A-frame capable of lifting 3.8 tonnes, a wide range of winches, side-scan sonar, sub-bottom profilers, and magnetometers, the vessel supported an array of scientific activities—from fisheries research to ocean physics and marine geology.
Over the years, Kaharoa played a critical role in New Zealand’s inshore fisheries management. The vessel supported stock assessments of species such as tarakihi, snapper, and red gurnard, helping ensure the sustainable management of these valuable resources. These surveys contributed to time-series datasets that underpin decision-making by Fisheries New Zealand. It’s no surprise that Kaharoa was central to intercalibration trials with Kaharoa II before her retirement, ensuring that the integrity and continuity of this long-standing data series are maintained going forward.
The vessel’s retirement is not just the story of a ship reaching the end of its service life—it’s also about the transition to a new generation of research capability. Kaharoa II, built in Vigo, Spain, represents six years of design and development, driven by the input of NIWA scientists and research partners. The new vessel is eight metres longer, features expanded lab and deck space, and is fitted with the latest technology. Importantly, Kaharoa II maintains a similar operating cost profile while offering enhanced research flexibility across disciplines.
According to Rob Christie, NIWA’s Manager – Marine Resources, the project was driven by the need for a modern, multifunctional platform capable of supporting not only fisheries and oceanographic research but also a wider range of maritime operations. The result is a purpose-built vessel tailored for the 21st-century needs of coastal and open-ocean science.
For Dr Richard O’Driscoll, NIWA’s Chief Scientist – Fisheries, the arrival of Kaharoa II is a welcome milestone. His team spends more than 130 days at sea annually on fisheries surveys. With the new vessel in operation, he sees an opportunity to build on the strong foundation laid by Kaharoa. “Kaharoa II will allow us to continue monitoring the abundance and distribution of New Zealand inshore fish for the next 40 years,” he noted during the vessel’s commissioning phase.
But for all the excitement surrounding Kaharoa II, the retirement of her predecessor is tinged with nostalgia. Many of NIWA’s longest-serving staff recall Kaharoa’s launch in 1981. Fisheries Research Director Duncan Waugh reportedly remarked on how smoothly the ship slid into the water at her launch—an omen, perhaps, of the reliable service she would go on to provide.
In the four decades since, Kaharoa became more than just a research vessel—she became a symbol of New Zealand’s commitment to understanding and managing its vast marine environment. She enabled research trips that yielded vital data for climate science, supported geological and ecological studies, and made the deployment of more than 3,000 Argo floats possible—devices that revolutionised global oceanography by continuously measuring temperature, salinity, and currents in the upper ocean.
Her modest crew complement of five scientists and five ship staff belies the scope of her achievements. Through storms and across oceans, Kaharoa proved that a small vessel could have a big impact. Her contribution to the understanding of New Zealand’s marine ecosystems, and to global scientific knowledge more broadly, will be felt for years to come.
As NIWA explores future options for the vessel—whether as a museum piece, training platform, or even a working ship in another part of the world—it’s clear that Kaharoa’s legacy is secure. She embodied the ethos of practical science, the power of well-maintained engineering, and the importance of long-term data collection in marine research.
