Upwind sailing requires a bit of precision. You have to keep your sails and boat on edge in order to make your way to windward. When you turn downwind, however, you can really cut loose!
Sails are eased as the boat heads off and the wind and waves send you off on what can be one of the most exhilarating rides of your life. Your local amusement park has nothing as thrilling as planing across the water and surfing down the face of a big wave. Or as relaxing as the thought of being lazily pushed along by the wind on a sunny light-air day.
"Downwind" sailing is a broad and inclusive term. Generally, any point of sail not close-hauled is considered to be "downwind". This includes close reaching, beam reaching, broad reaching and running. Reaching is going in a direction across the wind, while running is truly going with the wind.
A general rule of thumb in sailing downwind is that the more you head off away from the wind, the more you let your sails out. On a run, your sails should be eased as far as possible so their maximum area is exposed to the wind. Notable exceptions to this are catamarans and iceboats. When these boats bear off onto a reach, they accelerate quickly and build up their apparent wind. This makes them go even faster, which further increases their apparent wind and moves it forward. Even though the true wind is coming from behind, the boat is moving so quickly that it feels like the wind is coming from the bow. Therefore, the sail(s) must be trimmed in tightly. Like any boat, however, an iceboat begins to slow down when it heads too far away from the wind. This is because the apparent wind and true wind begin to work against each other, which reduces the apparent wind.
One of the major differences between upwind and downwind sailing involves how you steer the boat and trim your sails. Going upwind you generally pull the sails all the way in and then use them as a guide to steer the boat. When sailing downwind, however, you usually aim the boat straight for where you want to go, and then use this heading as a guide for how to trim your sails.
One of the easiest ways to steer downwind is to aim for an object such as a buoy or a point on shore. Be sure it is fixed, though. I can remember sailing in one overnight race where I was steering for what I thought was a light on shore. After a while, I discovered we were way off course. It turns out we had been following a slow-moving barge!
A more accurate means to steer is by using a compass. Aim your boat in the direction you want to go and note the compass heading. Then hold this course on the compass. In the situation described above, I could have known that my "fixed" object was moving if I had been watching the compass.
Another way to determine a compass course is to use a navigational chart. In fact, this is the only way to do it when you can't see your destination. The only thing I don't like about using a compass is that you have to stare at numbers. I'd much rather look around all the time.
Trimming Your Sails
Once you're steering a course you like, you must trim your sails accordingly. Ease the sails out as far as they will go until they just begin to luff along the forward edge; then trim them in slightly.
Since it is very difficult to steer a perfectly straight course, and the wind is usually shifting in direction and/or velocity, you must constantly adjust the sails in order to keep your boat performing optimally. Keep the sheets in your hands so you can trim or ease when necessary. Telltales on your shrouds or a wind pennant on the top of your mast will let you know the apparent wind direction and can tip you off to any changes that would require an adjustment in sail trim.
Another good sail trim guide are the telltales at the forward part (luff) of your sails. You can use the flow of these telltales to figure out how far to ease your sheets. For example, if the windward telltales are dancing (moving around), the sail is probably luffing slightly and should be trimmed. If the leeward telltales are dancing, the sail is stalled and needs to be eased. Ideally both telltales should flow straight back (or the windward telltales should be lifting slightly).
There are several other things you should consider when sailing downwind:
Centerboard -- Upwind the centerboard (or daggerboard) keeps the boat from going sideways and develops lift, which helps the boat move forward. As you head downwind, however, the board is much less critical because you are heading more in the direction that the wind is trying to push you. Therefore you can gradually raise the centerboard as you head off away from the wind. This reduces the drag caused by pushing the board through the water, which allows you to sail faster.
In general, you want to raise the centerboard just a bit on a tight reach, one-third of the way up on a beam reach, one-half on a broad reach, and three-quarters on a run. If your boat gets tippy, however, lower the board a bit for increased lateral stability. Be sure to lower the centerboard all the way before you turn back upwind.
Weight Placement -- The ideal fore-and-aft position of the skipper and crew varies according to wind and wave conditions. In light air, move your weight forward to keep the stern from dragging in the water (which slows you down). As it gets choppier, move back far enough to keep the bow from plowing into waves.
You also want to move aft as the wind increases. This will give you more stability because the aft sections of most hulls are flatter and therefore less tippy than the forward sections. In planing conditions, move your weight even farther toward the stern so the bow will lift up.
Your athwartships weight placement should also vary with the conditions. When sailing downwind, you want to have the helm balanced so the boat is steering straight. This minimizes drag on the rudder. It is best to let the crew sit in a comfortable position and then have the skipper move so the boat has a neutral, or balanced, helm. (The helm is said to be neutral or balanced when you can let go of the tiller and the boat continues in a straight line). Then by leaning in or out slightly, the skipper can steer the boat and at the same time feel the helm changes in the tiller. In general, it's good to keep the boat flat when going downwind.
When you have a windy tight reach, all crew weight will need to be hiking out on the windward side. On a broad reach, the crew may be to leeward and the skipper to windward. When on a run, you may even have to heel the boat a bit to windward to achieve a balanced helm. Athwartship weight placement also affects the boat's lateral stability. That is, the closer your weight is grouped near the centerline of the boat, the easier it is for the boat to roll. So spread as far outboard as possible whenever you need stability.
Spinnaker -- This is a large, full, colorful sail that you can set to improve your speed on a beam reach, broad reach or run. Handling a spinnaker takes a bit of practice.
Sailing by-the-lee -- Pretend you are sailing on a run and you head off even further so the wind is coming over your leeward stern quarter. This is called sailing "by-the-lee." It can be a dangerous situation because the wind may fill on the back side of the mainsail and cause an unexpected jibe, sending the boom flying across the boat with extreme force. This has not only caused many headaches, but has even killed some big boat sailors over the years.
There are several ways to tell when you are sailing by-the-lee: 1) You'll feel the wind coming from your leeward side (and you'll see it coming from this direction on the telltales and/or masthead fly); 2) the leech on your mainsail will start to flop back and forth; and 3) there will be very little pressure on your mainsheet. If you find yourself by-the-lee, head the boat up toward the wind, or jibe.
Wing and wing -- When you are sailing on a very broad reach or a run and you don't have a spinnaker, you can gain speed by "winging" your jib or genoa to the windward side. When the jib starts to collapse in the main's wind shadow, try pulling it over to the windward side to catch the wind.
On smaller boats, you can usually use your arm to hold the jib sheet out far enough to windward to fill the sail. But on bigger boats, you'll need something longer to hold the jib out far enough. Try using your spinnaker pole or a specially designed whisker pole (standard on racing boats like the Snipe or Star). Attach the end of the pole to the clew of your jib or genoa, and attach the other end of the pole to the mast. Then use the windward jib sheet to trim the sail.
You'll find there is a relatively small apparent wind angle where a winged jib will work effectively. If you head off too far, you'll go by the lee. If you head up too far, the leech of the jib will fold back on itself. But when you can make winging work, your boat will fly.
When it's windy, your boat can heel going downwind as well as upwind. Close and beam reaching are the most overpowering because the wind is blowing directly across your boat. There are several ways to control heel downwind. The most exhilarating of these is to use all of your body weight as leverage by hiking out to windward. Sometimes this will be enough by itself to keep the boat flat.
If you are already hiking and the boat is still heeling too much (i.e. you're "overpowered"), ease the sails so they luff slightly. This spills some of the wind and depowers the boat. Even though you are wasting wind power, the most important thing is to keep the boat generally flat. In puffy conditions, be sure to keep the mainsheet in your hand so you can ease the sail quickly whenever you get a puff.
There is one other good way to stop a boat from heeling. You can flatten a boat upwind by heading up toward the wind (called pinching or feathering). When you're going downwind, the way to reduce heeling is to head away from the wind. This lessens the sideways forces on the boat. Note that this is the exact opposite of sailing upwind.
Sometimes, when you are on a breezy run, your boat will start to roll back and forth until it seems a little out of control. There are several ways to minimize this. One that we already mentioned is to put the skipper and crew on opposite sides of the boat and use your weight to counter the rolling. At the same time, steer in the direction of the rolls so you keep the boat under the sails as much as possible. When the boat heels to windward, head up; when it heels to leeward, head off. Another way to prevent rolling is to overtrim your sails slightly and put more tension on the boom vang. You can also head up onto more of a broad reach. All of these should steady the boat.
Jibing (or gybing) is to downwind sailing what tacking is to sailing upwind. You still change from one tack to the other, but now your stern passes through the wind rather than the bow. The sails also change sides but since they are eased out for a broad reach or a run, they come across very quickly and with a great deal of force as the wind fills on their back side. Watch your heads when the sail crosses the boat!
The reason to jibe is usually that the other tack offers a faster course to your destination. Sometimes it may simply be that the other tack offers more sunshine. In racing you may have to jibe around a buoy as part of the course. Some boats, like iceboats and catamarans, or most boats in very light wind, go very slowly when they sail on a dead run. In order to get downwind, they jibe back and forth, maintaining their speed from reach to reach. This is called "tacking downwind" -- it's a lot like the zig-zagging you have to do to get to an upwind destination.
Before you jibe, check the position of the centerboard. It should be lowered most of the way to help stabilize the boat during the jibe. A contradiction occurs in windy conditions when you might think that lowering the centerboard all the way would provide more stability. In fact, the boat can "trip" over the extended board and cause a capsize. In this case, keep the board up about one-third of the way.
Begin your jibe by heading off away from the wind. The skipper should grab the mainsheet between the ratchet block and the boom. Right at the moment in your turn when you feel the pressure in the mainsail get soft, pull the sail in quickly toward the center of the boat; then let it go acropss the boat as the wind fills on the other side. In light air you can easily pull the sail across at any time; in heavy wind, however, you may need your crew to help throw the boom over.
The steering during a medium to heavy wind jibe is crucial. When the sail comes flying across, all the force of the wind is now trying to push the boat over to the new leeward side. This effect is compounded by the centrifugal force of the turn, and the result is often a capsize. To avoid this fate we must steer an "S" course. Begin the "S" by turning into your jibe. Just as the boom crosses the boat, turn slightly the other way so the boat is now aiming back under the sails. This keeps the boat from heeling too much right after the jibe. (Make sure the boom is crossing before you steer the other way, or the boom may not come across.) Once you are stable on the new jibe, head up to whatever course you choose.
During a jibe, the skipper crosses the boat facing forward, exchanging the mainsheet and hiking stick behind his or her back. The crew also faces forward and is responsible for getting the jib onto the new tack as well as making any gross weight adjustments needed to keep the boat level.
Since jibing is one of the most likely times for a capsize, it is smart to avoid jibing in heavy air until you gain more experience. In puffy winds, time your jibe so it takes place in a lull. If you are planing or surfing, however, the opposite is true. It is best to jibe when the boat is going as fast as possible so there is less pressure on the sails. This way they will come across most easily.
Planing and Surfing
For many people, planing and surfing is the most fun part of sailing. Only lighter displacement boats with relatively flat hulls will plane, but you can get most boats to surf.
Planing occurs when a boat is going fast enough to lift up out of her own bow wave and skim across the water. If you think there's enough wind to get on a plane, bear off onto a beam or broad reach. Move your weight aft and hike out so the boat is flat with a balanced helm. If the boat doesn't take off on its own, try a few quick and vigorous pumps on the mainsheet.
Surfing is just like riding a surfboard; instead of paddling with your arms to "catch a wave", however, you use your sails and weight to catch a ride. The idea is, like a surfer, to ride down the wave faces. Head up toward the wind to build speed and when you see a wave trough right in front of your bow, bear off into it. Once you get on the wave, ride it for all it's worth. If you start catching up to the next wave, turn slightly so you avoid plowing into it. When you start to slow down and feel like you'll lose the ride, head back up and accelerate again.
Pumping and ooching will often help break your boat onto a plane or surf. (Besides that, they're fun and good exercise!) Pumping is rapid trimming and releasing of a sail. It effectively increases the apparent wind on the sail during the pump and can give you the burst of speed necessary to plane or catch a wave. Ooching is sudden forward and aft body movement and is very effective in initiating a surf. Just as your boat is starting to go down a wave, ooch forward sharply. At the same time give the sail a sharp pump or two (I like to grab the mainsheet straight from the boom to make pulling easier), and off you go. When racing, there are rules that limit when and how often you can pump or ooch, but when you're not racing, you can pump and ooch to your heart's content.
When you first plane or surf, the extra speed may seem a bit scary. You should remember, however, that the faster a boat goes the more stable it will be. So enjoy yourself and your new-found speed. When you get a puff, remember to bear off under the sails and keep the boat flat. This will get you onto an even faster plane. To stop planing or surfing, slowly head up and luff your sails until your boatspeed drops. Put your centerboard down, trim in the sails and you are ready to go back upwind.