Wind is a weird thing. Some times it blows steady, but most times not. One gusty day seems different from the next gusty day. Sometime the gusts build up slow, sometimes fast, and some days it punches like a prize fighter. Once a gust catapulted me and crew to the middle of the sail, as the boat was slapped instantly sail-to-the-water. On gentle days, the wind puffs and dies, sometimes related to cloud shadows, sometimes not. The wind direction at the beginning of the gust can be different than at the ending of the gust.

Is there a book that explains wind, in a useful way to sailors ?

There are two that I know of, of which the best one is Frank Bethwaites "High Performance Sailing". Lots of good stuff in the other sections of the Bethwaite book, but the wind section is the best.

From what I've heard the books from North Sails Uni are very good: http://www.northu.com/.

I have found this one nice: "Wind Strategy" by David Houghton
& Fiona Campbell. Bethwaites books is very good but it requires a patient reader, willing to go over the sections more than once.

Also, Wind & Strategy by the same author. Extremely dense and technical.

I second the nod for Bethwaite's book. He's pretty biased toward skiffs being the best boat in the world...but there is a lot of really good information in there about wind and how to understand what is going on.

The books mentioned in previous posts are good. My favorite is still Alan Watts "WIND AND SAILING BOATS" from Quadrangle Books, One-Designh & Offshore Yachtsman Magazine, 1970.
"The structure and behavior of the wind as it affects sailing craft." 220 pages.
However, only Rick White and I are old enough to have a copy....
Dave Ellis

Writer,
there is a good selection of used "Wind and sailing boats" books at amazon.co.uk. I just ordered one.

Instant Weather Forecasting by Alan Watts

Since Watts was a Brit I'm not surprised to see copies on Amazon UK. They can ship to the US, I'm sure.
The later paperback Instant Weather Forecasting is of value, but the original book is MUCH more comprehensive.
Dave Ellis

You sure about Watts not being a Brit? If I recall he was formally trained in meteorology by the RAF, and after retiring from service started discussion and/or racing sailboats with his brother, prompting his book. Probably written in the 40's or 50's? You're right, the original is the one wanted, I had an opportunity to read a copy prior to a NAC campaign in the early 90's. The book was promptly returned to my skipper as it was considered a family heirloom, had been passed down three generations.

Guys,
Perhaps outside the scope of the original question, but do we have any winter reading tips when it comes to more multihull sailing oriented books? Like former olympic champs sharing tips or similar stuff.
Is Frank Bethwaites "High Performance Sailing" still the recommendation?
Best, J.E.

I like Stuart Walker. But he is difficult to read for many and his OSSSIC is a bit confusing to me as well. Where Stuart really shines is in tactics. His explanation of what it takes to win is timeless.

The Race,
I am not sure who it was by but it was really good.

Tim Zimmermann

The Race is not really a book about wind, more about racing around the world on a really big cat! A great read for the winter.

As far as "What is the wind doing?" get a good pair of polarized sunglasses so you can see the puffs coming down the lake. Of course the closer to the shore you are, the harder it is to see them coming, and lakes usually have big variations in both wind strength and direction, so you have to really pay attention when it's gusty. It is not uncommon to "tack" without ever changing direction when the wind switches, especially close to a windward shore.