A decommissioned 60-year-old fishing trawler, the Twofold Bay, was intentionally sunk off the coast of Hawke’s Bay to serve as an artificial reef and dive site. The project, led by the non-profit organization LegaSea, reached completion following three years of planning and a 10-minute scuttling process witnessed by a flotilla of approximately 40 boats. The vessel now rests in 17 metres of water near the edge of Pania Reef.
Did You Know? Before the Twofold Bay could be sunk, volunteers spent 800-plus man hours stripping the vessel of engines and oils to ensure the site was environmentally safe and compliant with the London Protocol.
How the vessel will support marine life
According to Chris Scott of LegaSea, the structure is intended to facilitate biodiversity regeneration in an area of the bay that is typically open and exposed. As the trawler breaks down, it is expected to provide a habitat for organisms including sponges, green-lipped mussels, barnacles, anemones, and sea squirts. These organisms are likely to attract fish species such as snapper, blue cod, and kingfish to the site.
Why the project matters
The creation of the reef represents a collaborative effort between commercial and recreational fishers, a partnership highlighted by Seafood New Zealand chief executive Lisa Futschek. Ngati Kahungunu marine scientist Shade Smith described the transformation of a former fishing vessel into a reef as a poetic “full circle” moment. He noted that the project underscores a broader need to transition away from bottom trawling toward active environmental restoration.
Expert Insight: This project demonstrates the potential for repurposing retired industrial maritime assets into ecological infrastructure. By aligning the site with existing natural structures like Pania Reef, organizers are attempting to create ecosystem connectivity, though the long-term success of such reefs depends on careful monitoring of how successfully they integrate into the local marine environment.
What happens next
The site is currently subject to an 18-month rahui, a period of restriction, before public access is fully permitted. Following this period, trust member Joe Reti anticipates that the community, including local rangatahi, will begin diving the area. Marine scientist Shade Smith intends to conduct regular monitoring to observe how the vessel develops into a functional reef system over time.
Frequently Asked Questions
How was the vessel prepared for the seafloor?
Volunteers spent a year stripping the boat of harmful materials, including engines and oils, to meet the standards of the London Protocol. Holes were then opened in the hull to allow the ship to sink intact using gravity and concrete.
Who approved the location of the reef?
The site was approved by the Mana Ahuriri Trust, the mana whenua of the area, who hold marine customary title for the location.
Can the public dive at the new reef immediately?
No, the site is currently under an 18-month rahui, which will restrict access until the period is lifted.
Do you believe artificial reefs are an effective way to restore marine biodiversity in exposed coastal areas?
