Step 9: Sailing downwind
By downwind sailing, I mean sailing on a "dead run." Sailing on a run requires having the sail in a different position than in normal sailing and it takes some concentration. On the plus side, it looks cool, it will get you home, and after mastering sailing on a run, a nonplaning jibe will be literally "a snap." Of course, before sailing downwind, you must be able to steer and tack so that you can get upwind.
Before taking the downwind (running) sail position, you must be on a broad reach. Now is a good time to reread the Steering section. Do not attempt to turn on to a run directly from a beam reach or higher. Head off the wind in the usual manner until you are sailing on a broad reach. Sail in that position for a bit.
To go into the running position, first move your hands back on the boom, and swing the sail across the front of your board as you did when you turned downwind (see Steering). The only difference between steering from a broad reach to a run is that the sail is moved more across the board and less forward. As you start to turn further downwind, move your front foot back so that it is even with your back foot, heels together. If you were successful in turning the board, you will be in the position shown below. If you did not turn the board downwind you (1) did not move your hands far enough back on the boom; (2) you did not lean the sail far enough across the front of the board.
In the downwind (running) position (1) the sail should be square in front of you (at a 90 degree angle to the board, (2) your knees should be bent, (3) you should press down on the boom.
In the downwind position, the board will seem very "tipsy," one rail will want to sink and the board then will want to turn in the opposite direction. To avoid sinking one rail or the other, you must be light on your feet. There are two ways to become light on your feet: (1) Go on a diet. (2) Bend your knees and aggressively press down on the boom. Pressing down on the boom will transfer your weight from your feet to the boom and mast. The first method of becoming light on our feet has never worked very well for us.
To steer in the downwind position, move the sail back and forth along the line (with arrows) indicated in the picture. Try to steer directly downwind by making steering corrections with the sail. When you are finished sailing downwind, steer off to one side or the other (on to a broad reach), and move one foot forward (i.e., resume the normal sailing position).
Now for the fun part. Practice sailing straight downwind 5 or 6 times. Each time, have your feet further back of the board. This will necessitate bending your knees and aggressively pressing down on boom. At the end of this exercise, you should be so far back on your board that if you were to let up on the boom, the tail of the board would sink (you would do a "wheelie"). Only after you can get that far back on your board are you ready to tackle the next step, a nonplaning jibe.
If you can sail downwind fine when the wind is light, but in strong winds, the sail gets blown out of your hand, get further back on the board. If you are far back on your board, the sail will be tilted toward the wind. Therefore, you can hang your weight down on to the boom.
Faster than the wind - More geek talk
How could a sailor go faster than the wind? Windsurfers do it all the time. The true wind speed might be 15 MPH, but windsurfers are screaming along going 20 to 25 MPH. Part of the answer to this (and other) mysteries is blowing in the (apparent) wind: Sailors make their own wind.
The apparent wind is the wind you feel as you move. For example, on a windless day if you are going north on an Interstate Highway at 55 MPH and stick your head out the window of your car, the apparent wind will be 55 MPH. In the other hand, if the wind is blowing 55 MPH in the same direction you are going, the apparent wind would be 0 MPH. In other words, the apparent wind is a combination of the true wind and your speed. The apparent wind can be greater than the true wind, and it is the speed of the apparent wind that matters for the sailor. The speed of the apparent wind can be illustrated with a "vector diagram" where the length of the lines indicates speed (in knots or MPH).
If a windsurfer is going fast, he or she is creating additional apparent wind. Going faster than the wind is one of the pure joys of windsurfing. The diagram also illustrates another mystery: When windsurfers are going fast, they always seem to be sailing against the wind (i.e., close hauled, with the sail sheeted in). The reason for this position is that the apparent wind is always forward of the true wind.
Next time an advanced windsurfer blasts by you, remember that she actually has more wind than you do. Somehow, it doesn't seem fair.
But then, it is rather magical.