Advanced sailing techniques
Now that you have made a few successful runs, we will cover a few more advanced sailing techniques. As you may have noticed, sheeting in and out is not the only way to control your speed. Changing course can also achieve the same results. Bearing off will effectively sheet the sail in, while bearing up will sheet out. Very often slightly altering your course will result in dramatic changes in speed.
Since altering your course changes your sail angle, it follows that you can sail many different courses simply by sheeting until the sail is at the appropriate angle to the wind. Depending on wind speed, sail type and your skill, it is possible to sail 45 degrees into the wind, so if you end up downwind of where you want to be, you can sail back upwind. You may have to take a zig-zag course back upwind. I don't recommend sailing downwind more than 45 degrees, especially in higher winds. Sailing just off the wind 10-20 degrees is probably the fastest course. Many sailors will make one leg of their runs slightly downwind for speed, then sail a bit slower upwind on the return leg.
At some point you may experience “hiking” which is having the upwind wheel come off the ground. Your first instinct will to panic and immediately sheet out, dropping the wheel back the ground with a thump. That's ok, it's a natural reaction. After you gain some experience you should be able to feather the sheet, adjusting the sail so that you can remain in a hike or let the wheel down gently. As the sailer tilts in a hike, the sail angle changes, presenting less area to the wind. This depowers the sail, reducing the side force on it, although if the wind is strong enough or you are sheeted too tightly you may still go over.
The sailer may also break the rear tires loose when overpowered. This can result in anything from a mild side slip to spinning out. If you sense the rear tires losing their grip, you can steer slightly into the slide and or sheet out slightly to reduce the side force.
There are several things you can do if you feel like you are sailing overpowered, the sailer is spinning out or sliding too much, or you keep going into an uncontrolled hike. First option is to reduce your sail size, either by switching sails or reefing the one you have rigged (I'll cover that later). Tire pressures also play a major role in the amount of traction. If you are constantly sliding or spinning, try reducing the pressure in your rear tires, a few psi at a time until you find a balance. You may find that different pressures work on different surfaces. For example, on my sailer with 4.80 x 8 trailer tires, I have found that 31 psi works on pavement, whereas on a dry lake I drop to ~25 psi. Keep in mind that too low of pressure will slow you down.