document noting measurements of an early GBE

In the late 1970’s, Auckland designer Malcolm Tennant was developing the Great Barrier Express (GBE) catamaran with the intention of creating a small, high-speed multihull capable of cruising the Hauraki Gulf.

photo of Klis III, a Bernard Rhodes Micromultihull trimaran
Klis III, a 24-foot Bernard Rhodes Micromultihull

Around the world, multihull classes with similar goals were beginning to emerge. An 8 metre trailerable racing class called the Micromultihull was growing in popularity in Europe, fostering competition between boats.

In the mid-1980’s, the Auckland Multihull Sailing Association held a design symposium around the Micromultihull class, presenting concepts from a number of local and international designers. Though the Micromultihull rule would never become established in New Zealand, over the next several decades, many of these designs were built, modified, and advanced.

a fleet of four 8.5 catamarans sailing together

The construction of so many boats over the years encouraged a great amount of research and design, and this information was used to create the 8.5 Class in 2004. The specifications were primarily based on the dimensions of the GBE, which was by then on Mark III.

The 8.5 Class committee maintains the rules, with revisions infrequent but consistent with current trends in mid-sized multihull sailing. For more information, including a full copy of the current Class Rule, boat reviews, and more, please click here.