International A-class catamaran


The A-Class Catamaran, often abbreviated to A-Cat, is a development class sailing catamaran for singlehanded racing.[1]

The A-Class Catamaran


The class was founded during the late 1950s and was part of the 4-tier IYRU (now World Sailing) approach to divide up the sports catamaran sailing scene into 4 separate groups. These A, B, C and D classes were governed by a very small set of class rules to which each design had to comply.[2] In the beginning it was just:

  • Maximum hull length
  • Maximum overall width
  • Maximum sailarea

All boats designed and built to these specs would be grouped into one fleet and race each other for crossing the finish line first.

The A-Class is the largest remaining of those 4 main classes. The ‘B’ class was a 20 ft twin hander with 235ft2 of sail and developed into the Tornado and a few offshoots such as the F18.  The ‘C’ class was another twin, but at 25 ft with a 300ft2 rig, has become a super sophisticated monster and the pinnacle of small cat design that races for the Little America’s Cup.  The ‘D’ Class was 32 ft and a sail of 500ft2 with three crew, but rapidly dwindled away. As a result, the 'A' class is the smallest, but still maintains its status as the ultimate sailing catamaran single handed design.


The official organisation for the A-Class catamaran is the IACA (International A division Catamarans Association).

The A-Class rules were expanded over time to prevent the cost of these boats from rising too high and to ensure fairness in racing.

Currently the main A-Class rules are:[3]

  • Min overall boat weight : 75 kg / 165.3 lbs
  • Max overall boat length : 5.49 m / 18.3 ft (= still the old IYRU rule)
  • Max overall boat width : 2.30 m / 7.5 ft (= still the old IYRU rule)
  • Max sail area incl. mast : 13.94 m2 / 150.0 ft2 (= still the old IYRU rule)

In handicap racing, the A-Class catamaran uses a Portsmouth Yardstick of 681 in the UK[4] or a D-PN of 64.5 in the USA.[5]

Current situationEdit

The A-Class design has over time converged to a single sail rig using a lightweight carbon mast of about 9 meters length and using lightweight pentex or Kevlar sailcloth. The hulls and beams are often made out of carbon fibre as well, although homebuilt wood or composite materials are still seen on the race circuits. This single sail rig (just a mainsail) allows these boats to truly excel when sailing upwind. Their lightweight and time tested sailing techniques make these boats very fast on reaches and downwind legs as well. They were often unbeatable on the race course and only with the introduction of the asymmetic spinnaker on other catamarans have they lost this position a little bit.

In the decades since their foundation the A-Class has gathered a significant international following and it has class organisations in many countries around the globe. Their world championships often attracts around 100 boats and sailors. It is also a class that still contains a significant portion of homebuilders, although their numbers are decreasing with every year due to the skills required to make a competitive boat. However, nearly all A-Class sailors tinker with their setups and boats. As it is a developmental class and the rules do allow so much variation, it is paramount that a top sailor keeps experimenting with new setups and generally tries to improve the design even more. Because of this general character of the class, the A-Class is often leading over other catamaran classes in terms of design development. Over time these other classes copy new findings for their own setups. Examples of such developments are: the carbon mast, the squaretop mainsail, the wave-piercer hull design and in general the use of exotic materials.

In 2017, with the advent of practical foiling designs, the IACA divided the class into an Open (Foiling) division, and a non foiling Classic division for boats with straight or C shaped foils, and with different class rules to prevent foiling. The two have slightly different SCHRS handicaps, the Open being 0.978, the Classic being 1.008. This allows close racing to continue and many older boats are still competitive on the Classic circuit particularly.


Apart from the list below of some of the commercial builders, the A-Class catamaran can be home-built:

  • Bimare (Italy) (
  • Aicher-Egner Technologie GmbH (Germany) (
  • Marstrom (Composite AB Sweden) (
  • Scheurer Design & Eng. (Switzerland) (
  • Scheurer Bootswerft AG (Switzerland) (
  • VectorWorks Sail (USA)
  • Wingfox (Poland) (
  • DNA (Netherlands) (
  • Vision (Netherlands) (
  • Nikita (Germany)
  • Exploder (Poland) (


World ChampionshipsEdit

Year Gold Silver Bronze
1981 Bontan Bay   Bill Anderson (AUS)
1982 Cesenatico   Alberto Babbi (ITA)
1984 Wellington   Allan Goodall (AUS)
1985 Spray Beach   Allan Goodall (AUS)   Greg Goodall (AUS) Massimo CORBARA ITA
1986 Brenzone   Scott Anderson (AUS)
1987 Blairgowrie   Brad Schafferuis (AUS)
1988 Turkey Point   Greg Goodall (AUS)
1990 Napier   Greg Goodall (AUS)
1991 Grömitz   Paul McKenzie (AUS)   Allan Goodall (AUS)   Greg Goodall (AUS)
1992 Silvaplana   Paul McKenzie (AUS)   Egidio Babbi (ITA)   Scott Anderson (AUS)
1993 Sanguinet   Egidio Babbi (ITA)   Paul McKenzie (AUS)   Scott Anderson (AUS)
1994 Lake Cootharaba   Mitch Booth (AUS)
1995 Andijk   Egidio Babbi (ITA) Dario MINELLI Roman STROBI
1996 L'Estartit   Glenn Ashby (AUS)   Scott Anderson (AUS)   Egidio Babbi (ITA)
1997 Long Beach   Pete Melvin (USA)   Scott Anderson (AUS)   Francesco Marcolini (ITA)
1999 Port Phillip   Nils Bunkenburg (GER)   Scott Anderson (AUS)   Cameron Owen (AUS)
2000 Cesenatico   Nils Bunkenburg (GER)   Glenn Ashby (AUS)   Egidio Babbi (ITA)
2001 Castelldefels   Steven Brewin (AUS)   Glenn Ashby (AUS)   Scott Anderson (AUS)
2002 Martha's Vineyard   Glenn Ashby (AUS)   Scott Anderson (AUS)   Steven Brewin (AUS)
2004 New Plymouth   Glenn Ashby (AUS)   Scott Anderson (AUS)   Steven Brewin (AUS)
2005 Sanguinet   Pete Melvin (USA)   Glenn Ashby (AUS)   Steven Brewin (AUS)
2006 Västervik   Glenn Ashby (AUS)   Scott Anderson (AUS)   Manuel Calavia (ESP)
2007 Islamorada   Glenn Ashby (AUS)   Lars Guck (USA)   Pete Melvin (USA)
2009 Belmont (AUS)   Glenn Ashby (AUS)   Steven Brewin (AUS)   Andrew Landenberger (AUS)
2010 Cesenatico   Glenn Ashby (AUS)   Steven Brewin (AUS)   Jack Benson (AUS)
2011 Århus (DEN)   Steve Brewin (AUS)   Scott Anderson (AUS)   Jack Benson (AUS)
2012 Islamorada Key   Mischa Heemskerk (NED)   Scott Anderson (AUS)   Jack Benson (AUS)
2014 Takapuna NZL   Glenn Ashby (AUS)   Blair Tuke (NZL)   Peter Burling (NZL)
2015 (ITA)[6]   Glenn Ashby (AUS)   Mischa Heemskerk (NED)   Manuel Calavia (ESP)
2016 Medemblik (NED) [7]   Mischa Heemskerk (NED)   Darren Bundock (AUS)   Steve Brewin (AUS)
2017 Sopot (POL) [8]   Steve Brewin (AUS)   Tymoteusz Bendyk (POL)   Jakub Surowiec (POL)
2018 Foiling   Glenn Ashby (AUS)   Mischa Heemskerk (NED)   Blair Tuke (NZL)
2018 Classic   Andrew LANDENBERGER (AUS)   Scott ANDERSON (AUS)   Graeme PARKER (AUS)
2019 Foiling[9]   Mischa Heemskerk (NED)   Dave SHAW (NZL)   Tymoteusz BENDYK (POL)

Class websitesEdit

  • International A-Division Catamaran Association (IACA) (
  • Australia (
  • Austria (
  • Belgium (
  • Brazil (
  • Denmark (
  • Germany (
  • Great Britain (
  • France (
  • Italy (
  • New Zealand (
  • Netherlands (
  • Poland (
  • Sweden (
  • Switzerland (
  • Spain (
  • United States of America (

See alsoEdit


  1. ^ "Archived copy". Archived from the original on 2010-03-07. Retrieved 2010-01-13.{{cite web}}: CS1 maint: archived copy as title (link)
  2. ^ "Archived copy". Archived from the original on 2010-02-21. Retrieved 2010-01-13.{{cite web}}: CS1 maint: archived copy as title (link)
  3. ^ "Archived copy". Archived from the original on 2012-04-18. Retrieved 2012-09-05.{{cite web}}: CS1 maint: archived copy as title (link)
  4. ^ "Portsmouth Number List 2012". Royal Yachting Association. Retrieved 31 July 2012.
  5. ^ "Multihull Classes". US Sailing. Archived from the original on 16 August 2012. Retrieved 30 July 2012.
  6. ^[dead link]
  7. ^
  8. ^ "A-CLASS WORLDS 2017 – A-Class World Championship 2017 Sopot". Archived from the original on 2017-01-14.
  9. ^