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How is it even possible for a boat to sail faster than the wind, let alone 2-3 times faster, like this AC72s of the 34th America’s Cup? That’s exactly what we’re going to find out in this video. Early sailing ships looked like this, and pretty much used their sails as big parachute like drag devices to pull themselves along in the same direction as the wind. This isn’t very efficient and it’s also impossible for any boat like this to sail faster than the wind. This is because as the boat accelerates the wind effectively disappears as boat catches up to it. Instead, modern sailing boats work much more like airplanes which use their wings to generate lift. Except on a boat the wings are oriented vertically instead of horizontally. One wing is the sails in the air, and the other is the daggerboard or keel in the water, also called a foil which is short for hydrofoil. The foil produces just as much lift as the sail even though it’s much smaller, and that’s because water is 800 times denser than air. Modern sails look much more like a streamlined airplane wing than a baggy parachute. They also generates lift in the exact same way. As the wind flows over a modern sail from front to back, the sail generates lift perpendicular to the surface of the sail, just like an airplane wing. Underwater foils like the keel on this monohull come in all shapes and sizes, but like the sails in the air they also generate lift perpendicular to their surface as the water flows over them from front to back. Except unlike an airplane, where the wings both generate lift in the same direction to lift the plane off the ground, the sails and foils on a sailing boat generate lift in opposite directions, and this is what propels the boat forward. The tighter the angle between the lift from the wind and water, the faster the boat will go. And the faster the boat goes, the more apparent wind it generates to flow over its sails, which generates more lift, which makes the boat go even faster. And this cycle will continue until the friction with the water prevents the boat from going any faster. That’s why the fastest boats have underwater foils that provide lift in two directions – a horizontal side force to counteract the forces of the sails and drive the boat forward, and a vertical component to lift the boat out of the water and reduce friction. None of this would be possible without high tech materials like carbon fibre, epoxy, and Dyneema, which can create structures stronger than steel at a fraction of the weight. Disclaimer: - This content is offered solely for your education and entertainment. - There are no warranties, expressed or implicit, about any content or its fitness for a particular purpose. - There are risks of injury, death, drunkenness, and financial hardship involved in sailing. - The skipper is always responsible for the safety of their vessel and crew. - Sailing Tips is not responsible or liable in any way for anything that happens on or anywhere near your boat or any boat that we are not in command of. #howto #sailing #howtosail #learntosail #sailingtips
