The 8.5 Class

Fast, fun sailing: the only words needed to describe this class of catamarans and trimarans established by the NZMYC in 2004. The long range, quick speeds, and comparatively low operating costs of Open 8.5 Multihulls makes them ideal boats for racing and cruising in a wide variety of environments.

String Theory sailing in Wellington
String Theory sailing in Wellington

The fleet is well-loved by sailors around New Zealand and the world. Boats are often built to be demountable and easily shipped in a container, and have been seen winning races from Alaska to Ensenada, and sailing in Australia, France, and beyond.

The Rule

The class follows a box rule: boats must fit within a box measuring 8.5 metres length overall, by 6.5 metres beam, by 12.6 metres air-draft (the distance from the waterline to the top of the mast). There is no minimum length requirement, though lower limits have been placed on weight and headroom to encourage robustness, eligibility for coastal races, and comfort for cruising.

The Class Rule, reviews of different designs, and other downloads are available here. You can also learn more about the history of the 8.5 Class here.

8.5 catamarans racing in Auckland
close racing is common — and adds to the excitement

Range and speeds

8.5s make distance racing more than manageable, easily completing the Coastal Classic in the daytime on any angle wider than a reach. They sail upwind at over 10kts, downwind at 15-18, and, on the edge of the envelope, can be pushed to over 24kts, flying hulls and spraying waves of white foam off their leeward bows.

GBE Voom with cruising boom tent
Voom! with her custom boom tent by Covers & Canvas


Upon reaching their destinations, 8.5s can be easily converted to comfortably livable cruising setups with boom tents and bean bags. Their trampolines are well-suited for gatherings, offering ample space for lounging and enjoying the scenery.

Get involved

happy crew of three sailing String Theory in Wellington

8.5s can be found racing in mixed fleets and cruising around the country. In Auckland, a fleet participates fortnightly in club racing with crews of 3 or 4 people. There is also an active fleet for Hauraki Gulf distance races, including the Coastal, the Gold Cup, and the two-handed SSANZ Lewmar Triple Series.

If you would like to learn more about getting involved, you can contact our class representative Ed at, or talk with owners and fans of the class in our Facebook group and the Multihull forum.