The International B-class/F20 Catamaran, is a development class, on the comeback after the fracturing of the original B-class, into the myriad of one design, off the beach cats we have today.
The International B-class/F20 Catamaran, is a development class, on the comeback after the fracturing of the original B-class, into the myriad of one design, off the beach cats we have today.
The B-class was founded during the 1960s and was part of the 4-tier IYRU (now ISAF) 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. [1] In the beginning it was just:
| Class | Max Length | Max Beam | Max Sail Area | Crew |
|---|---|---|---|---|
| A-Class | 18’ | 7’6” | 150 ft² | 1 |
| B-Class | 20’ | 10’ | 235 ft² | 2 |
| C-Class | 25’ | 14’ | 300 ft² | 2 |
| D-Class | 32’ | 16’ | 500 ft² | 3 |
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, while the recent development in wing sail technology, the C-Class is enjoying a revival.
In 1967, the then International Yacht Racing Union (IYRU, now ISAF) decided to run a week long series of trials (August 5–12) to determine the best "A" and "B" classes of catamaran design to be selected for International status. The trials were held at the Catamaran Yacht Club, Isle of Sheppey (a small island in the Thames Estuary, 50 miles to the east of London), Kent, UK. [2] The B Class was easily won by a Tornado sailed by Reg White and Bob Fisher, who took six first places out of nine races. The Tornado went on to be used for the Olympics from 1976 onwards. Nearly 50 years later, the Tornado is still one of the highest performing B Class catamarans.
Unfortunately the choice of such a beamy and thus difficult to trailer boat, left a massive hole in the market. Consequently the B-Class quickly splintered into a score of sub classes like the one-design Hobie 16's, Nacra 5.8, and more recently the Formula 16 and Formula 18 specifications with strict class rules.
The rigid specification of the Tornado [3] combined with splintering mentioned above, has meant there has been a virtual absence of a B-class specification for many years.
However the recent arrival of what are being called International F20 catamarans we are starting to see a revival of a class that could lead sailors into the future of high tech, fully foiling and affordable catamaran sailing.
The current trend is to create a box rule like the A-Class but relax the rules that are preventing it from becoming fully foiling. Public opinion is leaning towards avoiding the pitfalls of the Formula 16's and Formula 18's that excluded several existing designs, such that the new spec would include all existing sub-20 ft off the beach catamarans. These dimensions are stretched out to accommodate the three production fully foiling Formula 20's: the Nacra F20 FCS, [4] the Flying Phantom [5] and the Marstrom M-20 [6]
Subsequently the International F20 catamarans is defined by
Practical considerations:
A catamaran is a multi-hulled watercraft featuring two parallel hulls of equal size. It is a geometry-stabilized craft, deriving its stability from its wide beam, rather than from a ballasted keel as with a monohull boat. Catamarans typically have less hull volume, smaller displacement, and shallower draft (draught) than monohulls of comparable length. The two hulls combined also often have a smaller hydrodynamic resistance than comparable monohulls, requiring less propulsive power from either sails or motors. The catamaran's wider stance on the water can reduce both heeling and wave-induced motion, as compared with a monohull, and can give reduced wakes.
The Tornado is a double handed multihull class recognised as an International Class by the International Sailing Federation. It was used for the Catamaran discipline at the Olympic Games from 1976 to 2008.
Hobie Cat is a company that manufactures sailing catamarans, surfboards, sailboats, kayaks, stand-up paddle boards, and pedalboards as the Hobie Cat Company. It was founded in 1961 by Hobart Alter, who originally manufactured surfboards. Its line of products has included more than twenty sailing craft, plus a variety of other watercraft.
The A-Class Catamaran, often abbreviated to A-Cat, is a development class sailing catamaran for singlehanded racing.
The Formula 18 class, abbreviated F18, is a non-foiling, restricted development, formula-design sport catamaran class. It was started in the early 1990s and quickly grew getting class recognition by World Sailing, with large racing fleets all over the globe.
The Formula 16 (F16) sport catamaran is an ISAF recognised 5 m long beach catamaran with an asymmetric spinnaker setup.
Taipan Catamarans are sailing catamarans, available amateur built or manufactured by Australian High Performance Catamarans (AHPC).
A beachcat is an off-the-beach class of catamaran ("cat") sailboat.
A sailing hydrofoil, hydrofoil sailboat, or hydrosail is a sailboat with wing-like foils mounted under the hull. As the craft increases its speed the hydrofoils lift the hull up and out of the water, greatly reducing wetted area, resulting in decreased drag and increased speed. A sailing hydrofoil can achieve speeds exceeding double and in some cases triple the wind speed.
Fernando Echávarri Erasun is a professional yachtsman in the Olympic Tornado Class. Teaming with crew Antón Paz Blanco, he became the Spanish, European, World Champion, ISAF Sailor of the year in 2005, Olympic gold medallist at the 2008 Summer Olympic Games held in Qingdao.
The Topcat is a one-design sailing catamaran boat class which is divided into several boat sizes.
The C-Class Catamaran is a high-performance developmental class sailing catamaran. They are very light boats which use rigid wing sails and can sail at twice the speed of the wind. They are used for match races known as the International Catamaran Challenge Trophy and its successor the International C-Class Catamaran Championship - both often referred to as the "Little America's Cup".
Nacra Sailing is a Dutch company that manufactures a line of small catamaran sailboats, or beachcats. NACRA was founded in 1975 to tap into the market created by Hobie Alter the founder of Hobie Cat, and several other companies offering small fiberglass catamarans designed to be sailed off the beach by a crew of one or two.
The Nacra 17 is a performance catamaran used for sailing. It was designed in 2011, went into production in 2012 and has been the focus of multihull sailing at the Olympic Games since its conception.
The Nacra F18 Infusion is a Dutch Formula 18 catamaran sailing dinghy that was designed by Morrelli & Melvin, Vink, Larsen, Young as a one-design racer and first built in 2008.
The Spitfire is a high-performance catamaran used for training and racing. It was designed by two Olympic gold medalists in the Tornado class, Reg White and Yves Loday.
The Nacra 15 is a performance catamaran used for racing. It went into production in 2015. It was designed as a smaller version of the Olympic multihull class, the Nacra 17.
The M32 is a class of sailing catamaran designed by Göran Marström and Kåre Ljung and first built in 2010 by Marstrom Composite AB. The design and production rights were sold in 2013 to Aston Harald Composite AB led by Håkan Svensson and run by Killian Bushe.
The Hobie 17 is an American catamaran that was designed by John Wake as a single-handed racer and first built in 1985.
The Nacra 20 is a catamaran sailing dinghy that was designed by Gino Morrelli and Pete Melvin as a one-design racer and first built in 1998.