Continuation of Racing to Win by Steve Milby
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One of the greatest hazards of yacht racing is that the skipper will contract a case of the “Blighs,” demanding perfection from himself and his crew, and taking it as a personal affront every time another skipper calls out a right-of-way rule. The experienced skipper knows that no crew error will be nearly so damaging as his own errors, and that browbeating his crew will ensure the occurrence of more errors. A crew member who has been criticized will become nervous, and is sure to drop a winch handle or fumble a sheet during a tack. If a mistake is made, calm your crew member. Assure him or her that the mistake is minor, and encourage him or her to correct it and forget about it. The experienced racer also knows that skippers hail competing boats to alert them to an action that is about to take place. These communications between boats contribute to the safety of all boats, and help them avoid misunderstandings. They should never be done to intimidate, embarrass or fool a newbie, and you should never be offended if another racer hails you.

Whether you sail a Catalina 25 or the newer 250, you will gain new respect for it when you start racing. They have the same basic rigging as the big boats, they are forgiving, you don’t need a killer crew to race them well, and there are very few 25 foot racer-cruisers that can get to the finish line so quickly.
So, the next time you see the racers heading out for the racecourse, join them. It will enhance your sailing skills and enrich your opportunities for social interaction. If you are an experienced racer, encourage the newbies to come out and play, and consider it your responsibility to ensure that they enjoy a positive learning experience.
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The Scope of This Article

This article is not intended to be a comprehensive discussion of racing techniques. My purpose is to discuss a few specific techniques and concepts that I have found particularly useful through the years. Some of these techniques have not, to my knowledge, been widely discussed in the “How To Race” books, but they are frequently used by experienced racers. Some of them are my own variations on well-known techniques. A few of these techniques are generally considered fairly aggressive, and should be used with restraint. Aggressive tactics should never be used against anyone but experienced, race-toughened opponents. Many newbies and casual racers are turned off by the use of aggressive racing tactics, and over-aggressiveness is one of the main reasons many sailors cite for not participating in the sport. We all owe it to our sport to encourage others to participate in it.
Before we talk about specific racing techniques, however, we should first be sure that we clearly understand the most basic physical principles that make sailboats work.
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The Physics of Sailing

The Keel

When the wind blows on a leaf that is floating on a pond, the leaf will invariably drift downwind. It cannot drift toward the wind.

The keel of a sailboat is the device that enables the sailboat to sail against the wind. A sailboat without a keel would be like a leaf on a pond. It could only drift downwind. 

Imagine that you have a large vat of jello. If you plunge a wide-bladed sword into it, and then pull the sword toward you with the knife-edge first, it will be very easy to pull it through the jello. But, if you pull the sword toward you with the broad, flat side first, it will be very hard to pull it through the jello. The knife-edge of the sword provides very little resistance to the jello, but the broad, flat side of the sword provides a great deal of lateral resistance.

Now, notice the shape of the keel of a sailboat. Viewed from the front, it is very narrow. Viewed from the side, it has a very broad, flat surface. When the keel is suspended underneath a sailboat, the narrow edge of the keel is presented fore-and-aft, and the broad, flat surface is presented to the side. The shape of the keel will allow the boat to move forward quite easily, but it will strongly resist any sideways movement of the boat. 

When the wind blows on the sails, it increases water pressure on the wide, flat side of the keel. When pressure is applied to any surface, the pressure will seek out the path of least resistance, and the pressure will release in that direction. Since the keel strongly resists any tendency of the boat to move sideways, but it provides only slight resistance to forward movement, the boat will move forward.
In addition to the lateral resistance that is created by the keel, the shape of the keel also generates lift to windward as the keel moves through the water. A fast flow of water over the surface of the keel creates more lift, and enables the boat to sail closer to the wind without side-slipping to leeward.
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The Sails

Imagine that you are looking down on a sailboat from a position above the top of the mast. The 150% genoa and mainsail are trimmed for close-hauled sailing. Notice the distance from the bow of the boat to the mast. Next, look at the trailing edge (leech) of the jib. Notice that the distance from the leech of the jib to the surface of the mainsail is less than half the distance from the bow of the boat to the mast. 
As a sailboat moves forward, it gulps huge quantities of air in the large opening between the bow and the mast, and the jib funnels that air into the narrow slot between the mainsail and the jib. When the slot narrows, it creates a venturi effect. The venturi causes the air pressure to increase as it passes through the narrow slot. After passing through the venturi, the wind generates more power than it would have, had there not been a venturi. This principle is important, because it helps us to understand the importance of precisely trimming the mainsail and the jib in relation to each other, so that the slot between the mainsail and the jib is neither too wide, nor too narrow. When the leading edge of the mainsail begins to lift and flutter, that tells you that you are trying to stuff more air into the slot than the slot is capable of accepting.

When you decide to sail on a beat or a close reach, you should first adjust the jib for the course you wish to sail. Next, you should adjust the mainsail tighter than necessary, and then slowly ease out the mainsheet until the point at which the luff of the mainsail just begins to lift and flutter. That is the point at which the venturi effect is maximized. If the mainsail is eased out too far, it makes the slot too narrow, and the sails lose drive. If the mainsail is pulled in too tightly, it makes the slot too wide, and the wind pressure through the venturi is not as high as it could be, and the sails lose drive. 

The reason why you adjust the jib first, and then adjust the mainsail afterward is because the jib must be adjusted in relationship to your intended course, and the mainsail must be adjusted in relationship to the jib. You trim your jib in accordance with your intended course and the wind direction, so that, when you are sailing on that course, the wind moves smoothly over both the concave and convex surfaces of the jib. After the jib is trimmed correctly, then the mainsail has to be trimmed in correct relationship to the jib, so that the venturi effect of the slot is maximized. If you do it any other way, you have to re-adjust both sails repeatedly, in order to find the right combination by trial and error.

Now, imagine that you are looking down on the imaginary sailboat again, and notice the curved shape of the sails. When a boat is running downwind, the wind pushes on only one side of the sails, and the boat cannot go any faster than the wind itself. However, when the boat is sailing to windward, the sails can be adjusted so that the wind passes over both sides of each sail. As the wind passes over the concave side of each sail, it pushes on the surface of the sail. As the wind passes over the convex side of each sail, it creates a vacuum, and pulls the boat in that direction. For maximum sailing efficiency to windward, your objective is to balance the pressures on both sides of the sail. The combined pressures on both sides of the sail generally enable the boat to achieve greater speed when on a beam reach than when going downwind.

If you are beating to windward, and you are steering the boat too close to the wind, the leading edges of the sails (the “luff”) will lift and flutter. They flutter because there is too much wind pressure on the convex surface of the sails, and not enough wind pressure on the concave surface. The term for this condition is “pinching.” The way to correct it is to pull the tiller slightly to windward, until the luff of the sail stops fluttering, and lays down flat.
If, on the other hand, you steer the boat too far off the wind, the wind will continue to push on the concave surface of the sails, but the air molecules will not be able to make the sharp turn around the leading edge of the jib and flow smoothly over the convex surface of the sails, and will not create the vacuum that generates power. As a result, the sails will lose power, and the boatspeed will diminish. The best way to know if you are steering the boat correctly is to apply telltales to your sails, and learn how to read them. When the wind is so light that it can’t move the telltales, then you must ascertain the direction of the air movement by some other means. In ultra light air conditions, the best way to ascertain wind direction is to watch smoke waft from a lighted cigarette or cigar, or from a piece of burning punk. After you have determined the direction of air movement, then you must be able to visualize, in your mind’s eye, the streams of air molecules moving over the surfaces of your sails, and adjust your sails accordingly. If you know how the wind behaves, then you can imagine the moving streams of air molecules, and you can adjust your sails so that the imaginary streams flow smoothly over the surfaces of your sails.

Telltales

When all the telltales on both sides of your mainsail and jib are streaming aft, and when the telltales on the leech of your mainsail are streaming aft, your sails are properly trimmed. When your windward telltales are streaming aft, but the leeward telltales are hanging down or fluttering, you should ease the appropriate sheet (jibsheet or mainsheet) slightly, so that more air is allowed to pass over the leeward side of the sails. When your leeward telltales are streaming aft, but the windward telltales are hanging down or fluttering, you should pull in the appropriate sheet (jibsheet or mainsheet) slightly, so that more air is allowed to pass over the windward side of the sails. When the telltales on the leech of your mainsail are not streaming aft, you should adjust the shape of the mainsail to correct that condition. Usually it means that the mainsail’s leech is cupped, and that condition can be corrected by flattening the sail.

Coordinating the Effects of the Sails and Keel 
A few moments ago I said that, as the keel moves through the water, it generates lift to windward. Likewise, as the sails move through the wind, they generate lift to leeward. The sailor’s objective is to maximize and coordinate the countervailing lift of both the keel and the sails, thereby driving the boat through the water as efficiently as possible.
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