Mates: I just got off the phone with a skipper who was having trouble docking under sail. Since he had the question possably there are other beginners who might have the same question. No matter how much you rely on your engine, one day you are going to have to sail into your slip so you may as well understand the correct way to do it.My first question was how is your slip positioned relative to the wind - is it upwind or downwind? His is downwind. My second question was what sail do you use to sail into your slip? He told me he uses the main - big problem!! I asked him to describe what happens when he sails in with the main and he told me he almost goes through the dock every time!! The reason he called me was he felt he was doing something wrong but did not know what it was. His problem was he was using the wrong sail.The correct sail selection is simple. You use the sail farthest from the wind. With a downwind slip it is the jib and with an upwind slip it is the main. The downwind wind approach is the trickiest and requires some practice. In other words, you have to release the jib some distance from the slip and just drift in. What that distance is depends on the boat and the wind speed.The upwind approach is pretty simple. As soon as you turn upwind the boat will want to slow down and if you really have to slow your progress, all you have to do is push the main way out and it will serve as a brake.My slip is an upwind slip and about 4 from the end of the dock. I really have to be careful because the wind is blowing across the narrow slipway and over my beam and I only have one shot at it. Once I turn upwind and into the slip the force of the wind slows me down but again I have to be very careful. The harder it is blowing the more cautious I have to be. The slipway on the other side of me is very wide and that would make sailing into the slip pretty easy. Most guys use a series of "S" turns to slow down and they gently glide into their slip. With my slipway, "S" turns are not possable.So the time to learn how to do this is not the first time you have to attempt it due to an engine malfunction. Pick a relatively calm day and try it a couple of times in your turning basin. When you feel comfortable in your ability to control the boat under sail, give your slip a try. It is fun to sail in and when done correctly in front of your dock nieghbors, they will think you are beyond cool and a great seaman!! When you step off your boat to tie off, don't look at them. Just act like you do this all the time!!