Rig Tuning Presentation with Michael McNamara at RYA Suzuki Dinghy Show 2016

Over the next short while, we're going to look at how sailors—the job of sailors—is to make the boat go around the racetrack as quickly as possible, irrespective of what else is happening. Whether they're in traffic or by themselves, whether in a gust or a lull, waves, flat water, obviously that potential speed will vary, but it's our job to make sure that we get as close to that potential speed as we can. Our environment is complicated, but luckily, thank goodness, the actual principle that defines how a boat moves is actually pretty straightforward.

What actually happens is somewhere up here in the sails, movement is generated. That movement is then moved to the hull through the mast, then through the shrouds, and it's only then that the hull starts to do its business and actually starts to go through the water. And it's only then that the sailors can actually do their business with that movement in order to make sure the boat is going as fast as possible all the time. We have two different jobs. First of all, job number one is to make sure that the sails are delivering the maximum amount of squirt that they possibly can. But it's no good just having the most beautiful setting sails if we're then presenting to the water a hull that's inefficient. Our job is to not only make sure the sails are going as quickly as possible, but also to make sure that hull is minimizing the drag, the least amount of resistance to the boat through the water. Golden rule number one is that the boat must be upright. Designers habit so the right-hand side and the left-hand side of the same J shape. If we don't allow the water to go round those curves, we're going to get an asymmetrical hull form, creating different ways, creating turbulence, and we're going to go slower. Now, because this is so important, how on earth do we know that we're getting it right? And we're so lucky—helms have to do... all helms have to do is just ease their grip on the tiller. If the tiller stays down the centerline of the boat, the boat is making the least amount of resistance. Water's going from her front to back round the same curves. If the tiller moves one way or the other, then we're creating more resistance than there should be. The tiller will always move to the problem area. So if the tiller moves too leeward, the boat's heading over to leeward, much harder to achieve. If it moves to windward, then the boat's heeling to windward. Release your grip on the tiller. I don't know, not that often—20, 30, 40 thousand times a leg—just to be a hundred percent sure that the boat is dead upright. The main problem is not when we're beating or reaching; the main problem with this is on a run.

How do you put it? Elderly—perhaps more, not perhaps—definitely overweight helms are sitting to leeward, you know, leaning on the boom because that gives their elbows something to do. What are they going to do? The likelihood is that the young crew on the windward side playing the spinnaker is not going to be able to keep the boat upright. And it's on the run that if you're going to make a cock-up, even on the run, you have the maximum amount of damage. Going with the wind, this lack of movement—sails hardly moving—we're in dead trouble. Make sure the tiller is eased from time to time in order to check the boat's upright. The other thing we have to do is just check what's happening where we've been. What's the wash like? Obviously, I hope it will be clear: the smoother the wash, the faster the boat will be going. Think about a flat-out plane. Think about if the water is billiard-table smooth behind the transom, and yet 20, 30—depending how fast we're going—40 meters behind the boat, there's a sort of rooster tail where the side washes meet. That rooster tail is the water saying, 'Bugger it, I'm going to create turbulence here.' And so far as the water is concerned, the boats are 30, 40, 50 meter long boats, so no wonder they go. Sadly, we can't always plane, but we can monitor that performance even when we're hardly moving by looking at the size of the bubbles. The flatter the wash, the smoother the wash, the less turbulent the wash, the faster the boat will go. Further forward, just to check all that doesn't look so good, nibble back a little bit just to see. Once we've got that sorted, we can then start to talk about how to deal with how the sails are maximizing the available squirt.

A sail works—any sail, main, jib, spinnaker when it's reaching—any sail works when we're beating and reaching by separating the airflow. Some of the air will go round on the windward surface, and some of the air will go round on the leeward surface. We don't need to get too complicated. All we need to know is, as a result of this separation of airflow, a pressure gradient is created between the more dense air on the windward side and the less dense air on the leeward side. There is therefore a movement from the dense air to the less pressure on the leeward side all the way around the camber of the sail. Some of it is a diagonal forwards bit, and when we're pinned in like Alex has got the sail at the moment, when we beat with a sail like this, there's a hell of a lot of sideways force, which is why when we're beating we have to do all that sitting out nonsense and stuff to keep the boat upright. And if we were mega stupid and overcook the leech, really hook the leech, then some of it would be actually drag going back the way we just come.

Although all three sails work when we're beating, when we're reaching, and the two sails when we're beating—working that way within the sail plan, different bits of the sails do different jobs. The job of the leading edge of the jib is responsible for how close a boat will point. But because the jib stops here, we've also got to include this bit of the main as well. So above the top of the jib and the leading edge of the jib are responsible for how close we can get the boat into the wind. If you're five degrees—only PCs can't measure five degrees—but if you're only five degrees further off the wind than you should be, do you know how much extra distance you're sailing? In half a mile, it's 75 meters. Now if you want the beating to last forever, if you like your tummy hurting, if you don't want to get on that reach, then for goodness sake don't point very well. But me, I want to get here, round out, and start the reaching stuff. So pointing as high as possible is dead critical to get this absolutely right. We have two controls: we have the angle of the sheet through the fairlead, which I'm going to do in a minute, and we also have the amount of retention. So let's do the sheeting angle first.

I'm not that bothered about the actual position of the fairlead. The rule I use is close enough: if you extend the line of the sheet from the fairlead through the clue and you extend it right down, if it's just below halfway, that's about right. Doesn't matter whether it's a Cadet, Albacore, Wayfarer, all of those sort of boats, RS200—so long as it's just below halfway, that will be about right. Because the critical thing—and this is why we have to rely so much on our pros—the big critical thing is the amount of tension post on it. Can you pull it in really tight, Alex? Right now look at the leech, please people. Now Alex is only going to ease the sheet—well, for youngsters, 25 mil; an inch for the rest of us. Right, okay, off you go. How much did the leech move? Pull it in that 25 mil, please. A hell of a lot, isn't it? So tiny little bits of sheet movement have an awful effect on the back edge of the sail. The ratio, believe it or not, is five to one. Every unit you move the sheet through the fairlead, the middle—where the spreaders are—will move five times that distance. We can use that movement in order to make sure we've got a constant angle of attack. And this is where we need to enlist the help of telltales. Half height, quarter height, half height, and three-quarter height. They will tell us what the air is doing. So if they're flowing, the air is flowing; if they circle, the airflow is broken down. If we've got the sheet tension right, all three telltales will be at the same sort of angle.

Now look what the effect—what Alex, that we're talking about the back of the sail—look at the effect on the front of the sail when Alex eases the sheet again. I'm going to put my finger on it. Ease away, please, Alex. Can you see what's happening? Sheeted in, please. And do it once more. Right. Leech tension not only controls the back edge of the sail, but as I've just shown you, it actually alters the angle of attack. So what we're trying to do: get the sheet to about halfway, and then nuances of leech tension in order to create the telltales working at the same sort of angle.

Golden Rule: the windward telltales—as soon as the boat's at walking pace, the windward telltales will be angled up. Three, four miles an hour, something like that, the windward telltales will all be angled up. Now why should they be angled up? Well, think about it. There's that amount of boat going through the air. What's going to happen to the air it's displacing? It moves up and up and up and up, so there is a diagonal upward movement over the leading edge of the sail plan, called upwash, simply by the passage of the boat through the air. And we've got to accept that movement. So if the telltales are all at 45 degrees angled up when we're at walking pace, the sheet tension is about right. If the top telltale stalls, starts to do its circle on the windward side, that means the leech is too slack and so the leech has got to be brought just a fraction—tiny amount, please, Alex—beautiful. If the top telltale goes, you tighten the leech just a snippet, just to get it to work. By the same token, if the bottom telltale starts to circle, you've stalled the bottom of the sail. This time the leech is too tight, so Alex has got to ease it. And you will find that very quickly you'll just learn the amount of sheet tension you need for any specific day just to get all three telltales angled up.

If you don't angle the telltales up, do another five percent rule—five degree rule—you're back into sailing 75 meters further than you actually should be. Absolute nonsense. I've actually had people tell me, 'No, Michael, I put both telltales at the same angle.' Rubbish. Get the windward one up as high as you can, and the faster the boat goes—for 20s, 470s, Fireballs, all that lot—the windward telltale will be almost vertical. The leeward telltale hasn't got the luxury of this air pouring over the windward side of the main, so the leeward telltales will be horizontal. If the leeward telltales are horizontal—the further apart we get them up—the closer the boat is pointing to the wind, the closer we're getting to the windward, and therefore the closer we can start that reaching stuff. The stuff we really like. Right now while we're dealing with the front of the sail, force three, beautiful little breeze, and then suddenly from Richard over there, an extra force five comes—black clouds, white horses, extra wind about. Help, how's my crew going to have to sit out? I might have to lean on him or something, you know. But not only does that extra gust have an effect on the heeling of the boat, it also has a big effect on what's happening to the front of the sail. As that horrible black squall rushes towards this poor dear defenseless jib, the effect of it—are you going to hold for a minute? In fact, stay put. What will actually happen is, under the onslaught of that extra wind, the front of the jib will sag away from the wind. The trouble is, as I'm showing here I hope, not only is it sagging away from the wind, but something else: it's getting fuller. Yes, right at the front. Can you see that? As it gets full right at the front, what's that going to do to the outboard pointing? It's going to send us back down the tubes. Think about it: not being able to point in a breeze, not being able to point close to the wind. The wind's going to hit you more from the side, more of that sitting out stuff. No, no, I don't think so. So what we've got to do is, we've got to look at the leeward shroud as our best judge of whether we've got the right amount of retention.

What we're trying to do is minimize the disaster of jib sag. We will know that if we look at the leeward shroud—if the leeward shroud is visibly slack, that means the mast's clunking over to leeward, we will have luff sag to excess, and that will affect our pointing. What I like to see—I'm sailing along whether it's in my Wayfarer, Albacore, Hornet, or whatever—I like to just see the leeward telltale just on the point of shimmering. If it's just on the shimmering, that's the best I can do, and that's good enough for me.

Now once we've dealt with the front of the jib, the air of course doesn't just stop here; it carries on its onwards passage. And this is where it goes to the speed-making machine. As it squeezes through the gap—as the air goes through the gap between the windward back of the jib and the leeward front of the main—it's an ever-narrowing gap. Because it's an ever-narrowing gap, the air has to speed up. As it speeds up, it becomes less dense. As it becomes less dense, it accentuates the pressure gradient between the more dense air on the windward side of the mainsail and the less dense air on the leeward side of the main. It makes the mainsail that much more efficient right at the front, right where the best part of the forward area is going, and gives us that squirt that we're so desperate for. So getting the slot right is our passport to windward speed. So how do we do it? We use sheet tension—nuances of sheet tension—to get all the telltales to work on the leading edge. And we do exactly the same thing, but can you see—I hope—we've fitted a leech telltale at three-quarter height. If that—let me show you—if that leech telltale is streaming, if air is jet propulsion off the back, air is going off both sides equally, that will stream. And that must mean the jib's at its most efficient. If that telltale breaks down, it will always go to the area where it's broken down. If Alex has sheeted it in too much, if the leech is too tight, the telltale will always go to the windward side. So not only are we looking at the telltales when we're looking at sheet tension—so pull it in a little bit, please, Alex. Right now you're going to ease about 20—right, eight-ish. Pull it tight. Is it about 20 mil? Right, stop. That's perfect. Trying to get that top leech telltale to set. If it's jet propulsion, the sail's right. By coincidence, what that will mean—and thank goodness it's by coincidence—is that the leech of the jib in this area here will be parallel to the centerline of the boat. On some classes like the Cadet, it's even more important tip—with a tiny little jib, it's desperately important to make sure that the leech is parallel. So how does the crew know that? What I do is I dive to leeward in the light stuff, I have a look at the leech of the jib, and I say to my dear crew, 'Dear old Alex, what I want you to do is to aim that part of the sheet—the aft part of the sheet—to a point on the transom. Put a mark there.' In the Wayfarer, it's where the side deck is; in the Cadet, it's where the leeward mainsheet block is. Just aim for there. And then, whether we like it or not, in light winds our crews—our Alexes—are responsible for the boat speed because they're down to leeward, they're looking at the leech of their jib, they're making sure that that telltale is working, they're making sure that the exit of the sail in the middle is dead parallel to the centerline of the boat.

What we haven't done is talk much about here—the problem with the mainsail. If you think about it, the problem with a mainsail is a mainsail is only a mainsail if it's got a jib in front of it. If it hasn't got a jib in front of it, it's a jib, because that's the first thing the wind is hitting. And therefore it doesn't matter when it's a Laser or a Solo or all those sort of boats, even your Merlin Rockets—above the top of the jib, the mainsail has to be sheeted as a jib. We've seen, I hope, with the case of the jib that the responsibility for organizing the angle of attack and the responsibility for organizing the leech came down to the amount of tension that the crew—Alex—put on the back bottom corner. And it's exactly the same with the mainsail. We've got various controls. We're going to do the mainsheet first. Alex, can you pull it in really tight? We've got various controls to control the leech of the sail. With the boom close to the centerline, the mainsheet has to be the control that's organizing the leech. Now you're going to ease it about 20 mil, please. About 20 mil. A little bit more. Right, look at this movement here, folks. Sheeted in about an inch, please, Alex. Way more than an inch—massive amount. So tiny little bits of tension on here have a hell of an effect up here. And because it's so critical, we're dead lucky that we've got a lovely guide. We're so lucky we've got this guide here. You will know, irrespective of the wind strength, whether the amount of load on the back bottom corner is right by looking at this bit here. This is the bit—how would you call it? This is the bit where the mainsail becomes schizophrenic. It doesn't quite know whether it's a main or it doesn't quite know whether it's—at this point here, so this is the point where it will always cause a problem. This is the point where it will always backwind.

So if the sail backwinds here, you can either mainsheet just a tiny amount to bring it into action. If the mainsail is backwinding here—by backwinding I mean air's hitting the leeward side—if air is hitting the leeward side, all we've got to do is tension the boom into the centerline just a little bit, just to bring it back into action. This boat here has got this wonderful bridle to stop very strong helmsmen from oversheeting, from pulling in too tight. Look at the effect: just ease it for a second. Look at the effect on the leech. If we overcome that bit more if you would. Right, okay, right. Now pull it again, please. How's that? Gone tighter? I'm going to have you cleated right. Cleat it, yeah. Watch: so vertical load on the back bottom corner has a hell of an effect on the leech higher up. It has an effect that will crucify the boat speed unless we use—as our motto, our reason for being, our only reason for being—mainsheet setting is just what is happening here. Golden Rule: is it backwinding? Yes? Sheet it in. Is it not backwinding? No? Ease it out. Because a sail is at its most efficient when it's deflecting the air the minimum amount possible. If we overdo it, we're going to hook the leech and we're going to go slowly.

Right, as soon as the boom's away from the centerline—can you move the boom away from the centerline as if there was a breeze? Quite away, please. I mean, just look what's happening up there. So the mainsheet can no longer take control of the leech tension. So now, please Alex, it's got to be the control of your kicking strap. Just watch the effect of tensioning the kicker. Right, again, just tensioning, loading the back bottom corner to bring the leech into play. How much again? It's dead easy. Is it backwinding? Yes, you need more kicker. Is it not backwinding? No, you need less kicker. It's as straightforward and as simple as that.

Now bring the boom back into the center, please. We're just going to look at the effect of the boom like this. We've already seen it—when they ease the mainsheet, the leech opened up like mad. Right, ready? I'm going to—I want you people over there will be able to see it. Look at the effect of mast bend. Keep it fitted. Look at the effect of mast bend when I pull the mainsheet over tight. Whereabouts is the mast bending? And look at the top, please, folks. Can you see, I hope, that most of the bend is being generated up here? Most of it's between here and here. Of course it's bound to be up there, of course it's meant to be a vertical tension, but a vertical load simply because of these—what I've done with the mainsheet. Right, now look at the difference in mast bend. Leave the mainsheet where it is here, or let the mainsheet out of suit, and then pull in the kicker. All this work, Alex—thank you. Good job you're a good trim. Right, okay. Look at the difference in mast bend now. Look what happens to the front of this mast—front of the sail—when you start to use the kicker. Off you go, then, please. Right, look here, folks. Right, ease it again, please. Now you're going to pull it in quite tight, please. All your strength, yeah. One—that's better. Right, now let it go.

Because the kicker—this wonderful gadget—because the kicker is angled at 45 degrees to both the mast and the boom, it's not only got a downward component, it's got a forward component. A component that thrusts the mast forward. Because the mast is bending, because it's thrust forwards, just look at the effect on sail shape. Yes, please, kick it quite a lot. What's happening is, because the mast is bending, the sail is getting wider. Because it's getting wider, it's getting flatter. Because it's getting flatter, the big plus—the wonderful plus—is it looks what it's doing to the slot. Hang on, stay put. I'm going to put my finger there. Let's get rid of that. Right, okay. Let it straighten the mast, please. Can you see, I hope? Right, so flattening out the front of the mainsail has this wonderful, wonderful positive thing of actually opening the gap between the jib and the mainsail, letting more air go through the gap. So we're organizing the kicker so that it's just not backwinding here. The byproduct of that—the wonderful byproduct of that—is that by using the kicker, it bends the mast, flattens the sail, opens the gap between the jib and the main. Why are we doing all this extra kicking? Why are we needing to do it? Because there's more wind about, more wind trying to pull through that lovely slot. So by bending the mast, we're overcoming the vertical strength of the mast and enabling more air to get through the gap. Ever so important on the Wayfarer with its big overlapping jib.

Now what we haven't done is talk about the back edge of the sail. Once the air is finished with the leading edge of the sail, it's actually got to come to the back of the sail. Have you ever been in that situation? Inland sailors will be well aware of this. What happens is, force three—lovely force three—suddenly the extra gust comes. As soon as that extra gust comes, if we haven't got enough kicking strap, what we actually haven't got enough downward load on the back bottom corner, what will happen is the sail will actually start to flog. Not backwind, but actually to physically flap. If it flaps, if it flogs, that's drag. Drag, of course, is slow. But it's even worse—the ride is terrible—but it's even worse what's happening to the boat underneath it. In windy conditions, if the boat's heeling over and not upright, that's usually because the mainsail is not being treated as a bomb door to be opened and closed according to how much wind is going through. If the sail is flogging, you will actually find suddenly power is generated, the boat heels over, dumps the power, and then the boat comes up. Boats dunked, and before you know it you've got a yo-yo, and it's really hard to organize.

What we're trying to do with the load on the back bottom corner—right, pull it in, please, kicking strap. Well done. Right, what we're trying to do—and now you're going to ease the mainsheet, please. Right, look at the leech, look at this angle here, this curvature here. Right, what's happened now is because the leech is firm, because the leech is solid, because the downward force is there, all the helm needs to do is to move the boom in and out according to how much wind is in. The helm from leaning on the boom for comfort—you know, if that's not enough, then the mainsheet's got to go out. As soon as the boat's upright, mainsheet's got to come back in. And all we're doing with that force on that corner is organizing backwind here, minimizing the backwind.

Now when it gets to the back edge of the sail, we've got gadgets. See dimming again, please, Alex. We've got gadgets on the back edge—telltales to tell us what's happening to the air. If the air is going off the back edge, if both sides of the sail are producing maximum, if the air is pouring off both edges so it's jet propulsion enough, the back edge will—the telltales will be streaming backwards. If the telltales break down and go one side of the sail or the other side of the sail, that means that the airflow is broken down on that side of the sail. It's more general that the airflow goes round on the leeward side. This time from four six to force two, the boat feels terrific. It's a real good son of the ocean as you're hammering through the wind. And then suddenly the wind stops, and the boat—what does it feel like? As if you're sailing through treacle. Now, sailing up on the Norfolk Broads, what was that? It's clearly I've sailed into weed, haven't I? I mean, it could be weed, but I tell you what it certainly is—is what's happened is because you had the sails set for four six, because you had the leech tension organized for four six, what's actually happened is the wind has switched off and the leech has gone bowing like that. And what's actually happened is that the air—since it's not going to follow those leeward curves, it's not going to go round all those edges—it's going to break off halfway across the sail. So right when you need maximum amount of squirt, you end up reefing your sail! For goodness sake, Golden Rule: at the first hint that it feels awful, mainsail out, please. Bring it right out, ease the kicker a little bit, and what we're trying to do is generate the backwind here. If in doubt, let it out. If in doubt, let it out until it backwinds here, and then bring it back in again. Please, pull it in, yeah. Just enough, just enough to get it to set here. And then just to be sure, object goes again, minimizing the curve that the air has to go round. If in doubt, let it out. Backwind—even with my eyesight, I can see the sail's backwinding and I can deal with it.

Which of the telltales is the hardest one to get to set? The bottom one—we're working nearly always beautifully well because it's got that lovely jet stream of air round through the slot, powering the air out the back of the sail. The top of the sail plan—the top telltale—is relatively easy to get to work by just organizing the tension. I reckon it's this one here. It's the leech telltale closest to the top of the jib. It's the leech telltale where the mainsail is in schizophrenic mode, not quite sure whether it's a mainsail, not quite sure whether it's a jib. One of these days, I don't know whether you can starch nylon to make it set all the time, but I don't worry about the second one down. It's got too much of a problem dealing with a problem that's happening there. So this is the one I look at. Have I got enough—enough tension to get the top telltale set? Is it jet propulsion enough? The back edge, then the sail's right. If it goes round to the leeward side, I've got to ease the kicker until it starts to stream, and then just gently bring it back on, being very aware that I don't want to go too far so I've got massive backwinding here.

Now there are two more gadgets we need to deal with. Right, bring the boom into the centerline, please, Alex. Put quite a lot of kicker on. Every—be so kind—bit more. Can you see that as Alex, because of this lovely powerful kicking strap, because of the forward force involved, he bent the mast. And because he's bent the mast, he compressed the back of the sail. Lots of wrinkles on that. Now if you had a photograph taken of that, how would you put it on the mantelpiece? Could you show it to Grandma? So what we can do is use the Cunningham—just enough, and only just enough. Got a bit more? Squidge, more squidge, more quicker. Right, well, just to tidy up most of it. If we have time, Golden Rule: kicker on to organize the leech tension. So this is all right. And if we have time, and if there's a cameraman about, of course, then we have to just organize the Cunningham.

Right, now just put a bit more Cunningham on, please, Alex. Right, okay. Now this is where we need to be brave. Are you ready for this? Look at the effect on the sail if he eases the kicking strap and straightens the mast, but he doesn't do anything to the Cunningham. Look at the full horror. Off you go. Okay. What's happened to the position of the flow? The flow's moved right forward, miles forward, right behind the mast. Well, what the hell, that doesn't matter? I tell you what, it does matter. Because if you guys look at the slot here, there just isn't any. This is the sort of gap between the jib and the main that will cause backwinding. And backwinding, the boat's going to go slower. Right, so let's get rid of the Cunningham. So the rule is: kicker on, and if you have time, flatten the sail also by pulling on the Cunningham. Kick her off and whatever ever there ever ever happens on that boat is that Cunningham must come off. Better to have the wrinkles—we can even call them speed bumps if we like—because at least the flow is back, at least it's allowing the air to curve around the leading edge of the sail and not have a right angle bend.

One last gadget. Clear out all, please, Alex. It's on the boom. Before we adjust it, just look at the shape of the sail here and look at the leading edge of the sail. In light winds, when we're beating, we want the foot so tight that it's really straining. This crease means fullness is coming out of it. By tensioning like mad, we're opening out this bit of the sail, we're making it as flat as possible to allow the slow, tired moving air to cling to that leeward surface as long as possible. Look at the effect on this bit of sail here when Alex actually starts to ease the clew. Thank you, Alex. Can you see that this point is moving here? Pull it out again, please. Right, I'm going to put my finger on it. Let it go off, please, Alex. Can you see it? A bit more—let it go a bit more. Right, can you see—I hope—that they were actually asking the air to bend round. Why should it do that? 'You must be joking, Michael, I'm not going to bother to do that.' And we're talking light winds here. So right when we want a maximum width sail, we have a sail where the air is breaking off over here, with a reefing at the back edge of the sail. In a breeze, we want the foot to be really, really, really tight. Not so much because we're bothered about the back edge, but because here—right, tension it like mad, please, Alex. Right. And okay, let it go, please. Okay. What happens is, if the sail is too eased at the front, what are we doing to the slot? We're closing the slot off, and yet there's more wind about. So bar tight when the crew is too heavy and the crew's inside the boat. Bar tight when the crew s'interpreux? Of course, same crew is too light and poor devils having to sit out like mad. But for that glorious five minutes on your birthday on July the 18th, you know, when the crew is the perfect weight, you can practice just ease the clew just a snip, just so that the sail is on the point of backwinding.

Now we've dealt with beating and reaching—by the way, the air separates on the sides of the sails. Now we need to do the run. Of course, when we run, and suddenly I'm afraid we can't demonstrate it here, but the run is slow. Everybody knows the running is slow. The run is slow because the very boat speed through the water reduces the amount of wind strength. Of course it happens. But do you know the main reason we go slowly on a run? Is because we have the sail area—when we're beating and reaching, both sides of the sail are working. When we're on a dead run, all that's happening is it's just pressure up the backside. But having said that, we've got to make sure that the air is able to escape, even on a run. And all we need to do now is boom out about two feet, if you would. Right, now you're going to cleat it up. You're going to organize the kicking strap. Right, pull it tight, please. Right, what we're after doing is looking at the middle leech—usually sail number area. If we've got the right amount of downward load on the back bottom corner—and remember it has to be from the kicker because the boom's away from the centerline—every time there's an extra little bit of an increase in wind strength, the middle leech will move forwards by about four inches—100 mils, something like that. If it doesn't move at all, it will stop the air escaping and the boat will go slowly. But shall I demonstrate if you've got it too loose? Certainly in the case of Wayfarers, Albacores, and such, shall I demonstrate what happens as the helm swims back to the centerboard because he's fallen—because you've rock-and-roll capsized. Just have enough downward tension on a run just so the middle leech moves forward every time the wind goes forward.

What we've got to do is to make sure that with symmetrical spinnakers, the spinnaker is brought round as far round as possible, not just to accept the wind that's coming up the chuff—important as that is—but also to accept the air that's pouring off the front of the mainsail. And that's why we've got to whisker pole as soon as possible to get the air pouring off the front of the mainsail. Of course, lollipop boats like these don't run anymore, you know. They don't give the marks down there. They don't go straight down there; they go over there first and then back over there. And you know why they do that? Purely and simply because they're still wanting the air to be on both surfaces. They're still wanting the air to go around both surfaces. Of course, there's extra distance involved, so they've got to go faster. So it's a trade-off between sailing the extra distance and actually saving the shortest distance. So with a lollipop-type boat, an asymmetric-type boat, we want the air going over both surfaces so that we broad-reach downwind. On a Wayfarer with symmetrical spinnakers, we want to just get them with the spinnaker around as close as possible to accept the air that's flowing off the front of the jib and the back of the mainsail.

So what we've done then is we've talked about the passage of air over the sail plan all the way around the racetrack. We've seen the effect of jib sheeting and retention on the front of the jib. We've seen the effect of mast bend and the kicking strap and mainsheet on the front of the mainsail—not only the front of the mainsail, but the effect it has on the back edge. But the one thing that I would strongly, strongly leave you with is: if in doubt, let it out. Because the front will backwind and you can deal with it. Never dictate, always react. That's it. Thank you very much.