Science Fair Project Encyclopedia
Windsurfing (also called boardsailing) is a sport involving travel over water on a small 2-4.7 meter board powered by wind acting on a single sail, that is connected to the board via a flexible joint. The sport is a hybrid between sailing and surfing. The sail board might be considered the most minimalistic version of the modern sailboat, with the major exception that steering is accomplished by tilting the mast and sail rather than with a rudder.
Windsurfers can travel over flat water as long as there is enough wind; they can also cut into breaking waves and perform spectacular stunts. Windsurfing is very versatile by its relation to the sailor. It can mean a peaceful relaxed pastime on the water to some people, it can be a high-stress high-adrenalin sport to others, but it can also be a lifestyle of seeking the endless limits of perfection in skills and self-expression.
Windsurfing is particularly enjoyable at wind strengths of Beaufort 3 or, better, 4 to 5.
Windsurfing is a wonderful sport for all ages (kids to retirees). It can be a bit costly (at least $1000) to get started but the rush it provides creates a quick addiction to most who will try more than a few time and get some speed.
Newman Darby was the first man who had conceived and idea of connecting a hand-held sail rig fastened with a universal joint to a floating platform for recreational use in the early sixties. Darby had organized Darby Industries, Inc. in 1964 to build what they called sailboards. However, Darby's boards were inefficient and did not enjoy significant popularity .
The fathers of windsurfing as we know it today was a Californian aeronautical engineer Jim Drake and his friend Hoyle Schweitzer. Drake has designed a surfboard-like board with a triangular sail and wishbone booms, connected to the board via a universal joint, and Schweizter popularized the new sport. The details of the original designs are available in his whitepaper on windsurfing. Also, the history of invention is discussed in this interview with Jim Drake.
Drake and Schweitzer patented the invention in 1968. Schweitzer incorporated Windsurfing International for promoting the sport and managing the patent, and bought the rights from Drake in 1973. Windsurfing caught on in Europe, and local companies started maufacturing windsurfing equipment. In 1983 Schweitzer sued a Swiss board manufacturer Mistral for infringing on his patent, however Mistral won the case by bringing up prior art by Darby. Schweitzer had to reapply for a patent under severly limited terms, and finally it expired in 1987.
Windsurfing has experienced a boom in the 1980s. Windsurfing became an Olympic sport in 1984, and a shortboard was invented around the same time. However, windsurfing was in a sharp decline in mid-1990s, as the equipment got specialized and hard to sail. Now the sport is experiencing a revival, as new beginner-friendly designs became readily available.
Boards used to be classified by into shortboards and longboards. Longboards are usually longer than 3 metres, have a retractable daggerboard, and are optimized for slower winds. Shortboards are less than 3 metres long and are designed for planing conditions. However, this classification has become obsolete in recent years as the sport has developed very quickly in materials and techniques, and longboards have nearly fallen out of use.
Shortboards, that is most boards produced nowadays, are designed to be used primarily in planing mode, where the board is sliding over the surface of the water, rather than cutting through, and displacing the water. Planing is faster and gives more maneuverability, but requires a different technique from the displacing mode.
Most windsurfers don't even consider sailing if the wind is not enough to plane. All shortboards should be planing with adequate, well tuned sails at wind speeds of 12 knots. The aim of planing at lower winds has driven the development and spread of wider and shorter boards, that plane at wind speeds as low as 8 knots.
Modern windsurfing boards can be classified into these categories:
- Boards meant for comfortable recreational blasting, mainly in flat waters. They typically fall into the volume range of 120–170 litres.
- Formula Windsurfing Class
- One metre wide boards for use in Formula Windsurfing races. See below for a more detailed description.
- Wave boards
- Small, maneuverable boards for use in the shorebreak. These boards allow to perform high jumps while sailing against waves, and let the sailor surf the face of a wave in a similar manner as surfers do. These boards usually have the volume of 70–90 litres.
- Freestyle boards
- Small boards geared at performing tricks on flat water. Usually 80–110 litre big.
- Racing boards
- Shortboards aimed at top speeds, rather than maneuverability or ease of use.
- Beginner boards
- these often have a daggerboard, are almost as wide as Formula boards, and have plenty of volume, hence stability.
- Racing longboards
- Mistral One Design, or RS:X class race boards.
Also, there are many attempts to bridge a gap between two of these categories, such as freerace, freestyle-wave, freeformula, and so on.
The original Windsurfer board had a body made out of polyethylene filled with PVC foam. Later, hollow glass-reinforced epoxy designs were used. Most boards produced today have an expandable polystyrene foam core reinforced with a composite sandwich shell, that can include carbon fiber, kevlar, fiberglass, epoxy, PVC, veneer, even plywood and molded plastic. Racing and wave boards are usually very light (6 to 7 kg), and are made out of carbon sandwich. Such boards are very brittle, and veneer is sometimes used to make them more shock-resistant. Boards aimed at the beginners are heavier (8 to 15 kg) and more robust, contain more fiberglass, or even have an indestructible molded plastic shell.
Currently, two designs of a sail are predominant: camber induced and RAF (Rotating Asymmetric Foil). Cambered sails have 1-5 camber inducers, plastic devices at the ends of battens which cup against the mast. They help to hold a rigid aerofoil shape in the sail, better for speed and stability, but at the cost of manouevrability and generally how light and easy to use the sail feels. The current trend is that only the large race sails have camber inducers. The rigidity of the sail is also determined by a number of battens .
RAF sails have battens which protrude beyond the back aspect of the mast. They have to flip to the other side of the mast when tacking or jibing, hence the rotation in the name. RAF sails have aerofoil shape on the leeward side only when filled with wind. They can be absolutely flat and depowered when sheeted out. This feature is much appreciated in the freestyle and wave riding disciplines.
In comparison with cambered sails, RAF designs offer less power and stability when sailing straight, but are easier to handle when manoeuvering. Also, RAF sails are much easier to rig.
The leading edge of a sail is called the luff . The mast is in the luff tube. The rear edge is called the leech. The front bottom corner of the sail, where the mast foot protrudes, is called the tack, and the rear corner, to which the boom is attached, is called the clew. The bottom edge, between the clew and the tack, is called the foot.
A windsurfing sail is tensioned at two points: at the tack (by downhaul), and at the clew (by outhaul). There is a set of pulleys for downhauling at the tack and there's a grommet at the clew. Most shape is given to the sail by a very strong downhaul, bending the mast in the luff tube. The outhaul tension is relatively weak, mostly just to keep the sail from flapping.
The sail is tuned by adjusting the downhaul and the outhaul. Generally, the sail has to be trimmed more for stronger winds. More downhaul tension loosens the upper part of the leech, "spilling" the wind at the gusts and shifting the center of effort of the sail down. In contrary, releasing the downhaul tension shifts the center of effort up. More outhaul makes the sail flatter, easier to control, but less powerful, and less outhaul brings more camber, more low-end power, shifts the center of effort to the front, and limits the speed by increasing the aerodynamic resistance.
Different sails are used for various disciplines of windsurfing: wave, freestyle, freeride, race. The main features of wave sails are that they reinforced to survive the surf, and are absolutely flat when depowered to allow riding the waves like the surfers do. Freestyle sails are also flat when depowered, and have high low-end power to allow quick accelerations. Freeride sails are all-rounders that are comfortable to use and are meant for recreational windsurfing. Racing sails, obviously, provide speed at the expense of qualities like comfort or maneuverability.
The size of the sail is measured in square metres and it can be anything from 3m2 to 6.5m2 for wave sails and from 6m2 to 12.5m2 for racing sails, with ranges for freestyle and freeride sails spanning somewhere between these extremes. There might be exceptions to these ranges, though, learning sails for children being as small as 1.7m2 and world-record speed racing sails being up to 15m2 large.
In windsurfing competitions, there are the following disciplines:
- Olympic Windsurfing Class
- Formula Windsurfing Class
- Super X
- Speed Racing
Freestyle and Wave are judged competitions, the sailor with best technique and diversity wins. Olympic Boardsailing, Formula windsurfing, Slalom and SuperX are races where many sailors compete on a course, and Speed Racing is a race where sailors compete on a straight 500 m course in turns.
Olympic Windsurfing Class
In Olympic Windsurfing 'one design' boards are used. All sailors use the same long boards with daggerboards and the same relatively small sails. This choice of equipment is motivated by the requirement that the board could be used in a wide range of sailing conditions, both planing and non-planing. This is especially important for its use in the Olympic Games, as the event has to take place regardless of whether there is enough wind for planing.
Currently Mistral One Design is the olympic class. It was introduced in the 1996 Summer Olympics. Before that, Lechner design was used in 1992 and 1988, and Windglider design was used for the Olympic boardsailing event in 1984 Summer Olympics. Mistral One Design will be replaced by in the 2008 Summer Olympics.
Formula Windsurfing Class
Formula windsurfing is quite a recent development aiming to revolutionise windsurfing by making the competitions more spectacular and less dependent on high winds. Formula is a class of boards about 1 m wide. They have fins or skegs as long as 70 cm and carry sails up to 12.5 m2. Contrary to the olympic class, sailors can choose boards of different models, as long as they are certified as Formula boards, and fit fins and sails of different sizes.
Large sails in combination with the 'wide-style' design allow planing in very low wind conditions. However, if these requirements are not met, the boards cannot be used and events will not take place, as non-planing sailing is very difficult with this design. Formula boards are only used on flat water.
Formula boards have excellent upwind and downwind ability, but are not very comfortable on a beam reach . This explains why the course is usually a box with longer upwind and downwind legs, or just a simple upwind-downwind loop.
Slalom is a fast funboard race in a course shaped like a figure of eight. Most of the course goes on a beam reach with floating marks that have to be jibed around. Slalom boards are small and narrow, and require high winds. Funboard class racing rules require the wind of 9-35 knots for the slalom event to take place.
This is a relatively new discipline in windsurfing competitions. It is a cross between freestyle and slalom. The competing sailors are racing on a short downwind slalom course, have to use duck jibes on all turns, and are required to perform several tricks along the way, such as jump over an obstacle, body drag or even front loop . The sailors are required to wear protective equipment in these competitions.
Speed racing competitions take place on a straight 500 m course. The sailors have additional 300 m to accelerate before their time is measured on the speed course. The sailors race in turns, and their time of course completion is measured.
Freestyle is a timed event which is judged. The surfer who has the greatest repertoire, or manages to complete most stunts, wins.
Similar to freestyle (though wavesailing preceded freestyle) except that the stunts are generally performed in surf and points are awarded for how well the waves are ridden. A Typical wave contest will score two jumps and two waves. A good heat would consist of a clean forward rotating jump, a backward rotating jump, a long slashy wave ride and a trick on the face of the waves such as a goita or 360.
A windsurfer holds an outright World speed sailing record: an Irish sailor Finian Maynard reached the average speed of 46.82 knots (53.88 mph or 24.08 m/s) over a 500 metre course on the 13th November 2004 at Les Saintes Maries de la Mer (France). This was exceeded on 10th April 2005, by the same sailor on the same venue at a speed of 48.7kts (at time of writing this has yet to be ratified). These performances brought back to windsurfing the record which has been held for over 11 years by an asymmetric wing-sailed trimaran Yellow Pages Endeavour.
- Boards Magazine, UK
- Royn Bartholdi's Freestyle page - a great resource
- UK Windsurfing Association - the "home of competitive windsurfing in the UK"
- World Wide Windsurfing Links
- International Mistral Class Organisation
- Official International Formula Windsurfing Class website
- International Funboard Class Association
- Professional Windsurfers Association
- Soulrider Windsurfers Community
- Windsurfing Croatia
- Windsurfing Lake Garda Italy
- An article on windsurfing history
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