About the designer

Bob Forster


My early experience with multihulls came with the building of a Trailertri 720 in early 80’s while working as a craftsman potter. This was followed by many years of enjoyable cruising and racing in this boat, as well as a concurrent involvement in the Trailable Multihull Yacht Association of Queensland in various administrative roles, including handicapping, the latter stimulating a keen interest in multihull design.

I worked for OSTAC Yachts in Australia the 1990s where I gained ‘hands on’ experience in all aspects of commercial multihull production, including the then ‘state of the art’ vacuum bag foam sandwich construction techniques used on the Farrier designed F-31 and the Mark 2 version of the F-24 trailerable trimaran, then built in Australia. The plugs and moulds for these boats were developed in Brisbane where I was part of the team involved in their production. Subsequently, I worked on the building and assembly of these boats. This period provided me with detailed experience in the various aspects of modern multihull construction, including vacuum bagging techniques, then in their infancy locally. At the same time, occasional ‘one off’ trimarans were built by the company, using cedar strip plank or Durakore for construction.
During my time with OSTAC, I rose to the position of production manager for the company, where latterly, the principal production was the Corsair 3600 cruising cat and the F-24 Mark 2 trailable tri. The company was also developing moulds for new and updated designs for Corsair Trimarans in America. I left the company when the joint owner of the OSTAC and Corsair Trimarans businesses decided to cease operations with OSTAC in Australia in the mid nineties and centre all the production of the company in America with Corsair Trimarans.

I am now well into my sixties and have been sailing on and off since I was a teenager. Initially, this was in dinghies, and later, with a young family, aboard a small 14’ “Off the Beach” plastic cat which gave me a taste for multihulls. A simple need for accommodation and a bit more comfort for the family led me to investigate Ian Farrier’s Trailertris, then starting to make a name for trailerable multihulls in my home city of Brisbane, where he built his first trimarans. This was the starting point for his now internationally recognized design career.

I built one of the early Trailertri 720s, “Potboiler”, launched in 1986. For those interested, a photo showing the tri being sailed on the edge, was featured heading up the home page of the Yahoo Groups Trailertri website.

There followed many years of sailing with a reasonably substantial local Trailertri fleet, many of them modified in various experimental ways, with and without designer approval. At the same time, other designs were appearing locally besides the Farriers, notably Tony Grainger’s more race oriented, sleeker lightweight ‘075’ designs, as well as occasional imported trimarans like the Quorning Dragonflys. In addition, via the sailing & multihull magazines, I absorbed a constant diet of new developments in the larger racing multihulls in Europe.

My interest in trimaran design really started with work on developing a local ‘Trailertri Rating Rule’ in the 1980s, based loosely on the then published Micro Multihull Rule and John Shuttleworth’s ideas on the performance factors affecting multihulls. At that time, the local Trailertri fleet provided a range of boats with similar hulls, but varying in length, weight, rig size and type. This provided an opportunity to test the viability of the rule against these parameters and modify it to fit the existing fleet. The rating was later extended to include all trailable multihull designs in the relatively small fleets contesting national trailable multihull regattas in Australia. This early rule has now been superseded in Australia and the South Pacific area by the “OMR”, an adaptation of the European Texel Rule. (See http://www.mycq.org.au/ )

My involvement in handicapping led me into wider research in the field of yacht design and multihull design in particular, including acquiring a basic CAD program to fair hull shapes and do the necessary hydrostatic calculations on the hull shapes in which I was interested.

Finally, the design, development and building of the prototype ‘Wavelength 780’ began as a ‘new boat’ retirement project in the late 1990’s.