High-tech "flying" boats battling for America's Cup

By Tessa Walsh

(Reuters) - Some of the world's fastest sailing boats will battle for the America's Cup, the oldest trophy in international sport, during high-octane racing in Bermuda in May and June.

The six teams competing have designed and built their own America's Cup Class catamarans.

These high-tech, twin-hulled carbon fibre boats are sailing's equivalent of Formula One cars and have a huge fixed "wing" similar to aircraft wings that allow them to "fly" above the water on hydrofoils.

Below is a summary of the key technical factors of the boats, based on data from the America's Cup organiser and the teams' websites.

* The boats can travel at more than three times the wind speed, reaching up to 50 knots (92.6 km per hour) and are designed to foil when sailing both with and against the wind.

* The catamarans are "one design" with hulls 15 metres long connected by trampoline netting. The boats are 8.48 metres wide. The hollow carbon wings are 24 metres tall and have an area of 101 square metres

* Key differences include the structure of the wing, "fairings", which improve aerodynamics and limit drag, the size and shape of the curved foil blades and the hydraulic systems

* The boats are sailed by a crew of six and steered with high-tech steering wheels. Sailors grind massive winches by hand or by pedalling, powering the hydraulic systems used to control the sails and foils

* Foiling is fast but unstable, and the winner is likely to be the boat that can stay out of the water on its foils the most

* It takes seconds to capsize the boats, but minutes to right them with the help of support boats. Avoiding high speed collisions will be vital to avoid injury and damage that could cost the race

(Editing by Alexander Smith/Mark Heinrich)