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Capsize Recovery and Bernoulli's Principle
http://www.hobie.com/forums/viewtopic.php?f=14&t=47678
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Author:  TarHeel 16 [ Thu May 23, 2013 7:04 am ]
Post subject:  Re: Capsize Recovery and Bernoulli's Principle

This has been a fun post to follow, but has anyone considered the phoenomenon Wind Gradient? It's the universal tendency of wind speed to increase with the height above water. Even on a windy day, the friction between air and water is such that the air immediately above the water's surface is barely moving. Within a foot or so of altitude the air speeds up dramatically, but it doesn't reach its maximum velocity until a good 30 feet or so above the water.

If you take this into account, you'll realize that there isn't that much pressure while the mast is in the water and as it raises, the wind's pressure will increase exponentially. I only mention this because it hasn't been brought up as a point here, but it is still a factor in the discussion and doesn't mean that I'd recommend pointing the mast into the wind. 45 degrees is still the way to go.

Author:  ASDASC [ Thu May 23, 2013 3:18 pm ]
Post subject:  Re: Capsize Recovery and Bernoulli's Principle

The other thing that is not to be forgotten is that when flipped, the sails fill somewhat with water. Pointing the hulls into the wind helps because the wind tries to get under the sail, emptying the water out of them. trying to right my H16 solo, it works well to get the mast just up out of the water by leaning back on the righting line until I am almost horizontal to the water, then walk back on the hull toward the stern. This fills the sail just a little bit and brings the mast up. Once it starts coming you, you are good to go as all the forces in the right direction start to multiply and you have to focus on going on over to the other side!

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