The 49er is a double-handed skiff-type high-performance sailing dinghy. The two crew work on different roles with the helm making many tactical decisions, as well as steering, and the crew doing most of the sail control. Both of the crew are equipped with their own trapeze and sailing is done while cantilevered over the water to the fullest extent to balance against the sails.
The 49er was designed by Julian Bethwaite (the son of Frank Bethwaite) and developed by a consortium consisting of Bethwaites, Performance Sailcraft Japan, Peter Johnston, and Ovington boats.
To handle a large and powerful sail area, the mast uses a square topped sail that causes the upper main to twist off and flatten, allowing a controllable sail with fast gust response and reducing the heeling moment. The use of solid wings, rather than tubes as on similar boats (RS800 etc.), makes it easier for the crew to run across the deck from gunwale to gunwale during maneuvers.
thumb|49er skiffs in a race
thumb|49ers at the Extreme Sailing Series in Boston harbor preparing to race, 4th of July, 2011
The 49er made its first Olympic appearance at the Sydney Olympics in 2000 and has continued to grow in popularity ever since.
With a Portsmouth yardstick Handicap of 740 the 49er is the fastest two person one-design monohull dinghy.
In 2009 the boat received a new rig design, including a larger fully carbon mast (replacing the aluminum mast) and square top (roach) mainsail.
Construction
As a one design class, the 49er has two licensed suppliers, Mackay Boats in Oceania and Ovington in Europe.
Hull
The hull is made of Epoxy GRP and foam sandwich laminate with carbon fibre in high load areas. It includes two solid wings, also called racks, that clip into the side to increase righting moment of the trapezing crew. Its length was fixed at 4.99 metres because the ISAF brief for the high performance Olympic class dinghy called for a 5-metre boat, but Tokao Otani, a member of the development consortium, pointed out that there was a tariff in Japan for boats over 5 metres long. It has a fine entry to efficiently transition between the low speed displacement, and high speed planing modes. According to the International 49er class rules, the minimum hull weight including all permanent fittings can not be less than 94.0 kg.
thumb|49er at the 2012 London Olympic Games
Spars
Southern Spars, part of the North Technology Group, is the licensed supplier of the 49er mast. It is a three piece male-moulded assembly made from 100% standard modulus carbon. It is 7.0 metres tall and capable of supporting a combined crew weight up to 165 kg from its dual trapeze. The mast is braced by three sets of shrouds that connect to a fitting on the side of the boat. The crew is able to adjust them by tightening or loosening them, depending on the wind speed and sea states.
The boom is made from an aluminium alloy extrusion.
Foils
The rudder and daggerboard are made from a composite of epoxy, carbon and glass, covered by a hard gelcoat surface. The head of each class legal foil carries the embossed 49er logo and the ICA label.