Difficult "off the lip" spins lift the surfer entirely off the peak of the wave and into the air. Surfers with advanced skills may turn in mid-air. Big-wave surfing is exactly what it sounds like: riding really large waves. The majority of surfers ride waves that are 3 to 6 meters (9-20 feet) high. However, some very skilled surfers have been known to take rides on waves that are as big as 10 meters (33 feet). Surfing has become very popular in recent years. There are now many clubs and organizations that promote surfing as a sport. Surfing is becoming more popular not only in tropical climates but also in cold places such as Canada and Northern Europe where there is enough wind to keep surfboards stable but not strong enough to cause injury if you fall off of one. When a surfer enters the water, they swim out about 30 yards from the shore or until they feel comfortable going further out. Once they reach this distance, they will usually wait for a wave to arrive. A wave is a series of water particles that moves toward the shore at a rate of about 1 foot per second. If a surfer sees this wave coming, they will paddle out to meet it. When the wave reaches them, they will stand up and skate away from the beach on top of the water while blowing into a tube attached to their board. They will then check out other waves and repeat the process until they find one they want to ride.