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vectors and the continual recalculation of wind angles and the Pythagorean Theory are central geometry concepts used regularly by sail racing tacticians and helmsmen.
1. America’s Cup: The America’s Cup is both the world’s most famous sailboat race series (other than maybe the Olympics) and is also the trophy awarded to the winner of the America’s Cup races. Racing teams from all over the world compete for this trophy. The America’s Cup is the oldest active sailboat race in international sport. The next racing series is already occurring and will culminate in 2013 in San Francisco.
2. Beating: When one sails a boat toward the wind, it is called beating.
3. Close Hauled Tack: When one is beating, and one is sailing as close to the wind without being in irons and not being in the no sail zone, one is sailing on a close hauled tack. In Etchells, generally the close hauled tack is 25 degrees off the wind direction.
4. Etchells: Etchells is a one design boat first created in the 1960s by boat designer, Skip Etchells. An Etchells is a sleek 30 feet six inches long sailboat that has a main sail, a jib, and a spinnaker. It is one of the most well-known competitive one class boats in the world.
5. Head-to-Wind: Head-to-wind is another sailboat racing expressing for being in irons.
6. In Irons: A boat cannot sail directly into the wind or its sails will flap and flog. When sails are flapping and flogging, you are sailing into the wind and your boat cannot move forward. This sailing condition is called “In Irons.”
7. Lay Line: A lay line is the course on which a boat sailing as close to the wind as it can without going into irons and can make the mark without altering course.
8. Mark: A Mark is a buoy, float, or other geographical element (like a lighthouse) that boats sail around in a race.
9. No Sail Zone: When a boat is in irons, a boat is in the “no sail zone.”This means that the boat cannot move forward against the wind.
10. Off the Wind: When a sailor is not sailing on a close hauled tack, his boat is off the wind.
11. Port Tack: If one is beating close to the wind and the wind is coming over the left side of the boat, one is on a port tack. The sails are on the right or starboard side of the boat.
12. One Design: One Design boats are identical boat designs that use the same sails and equipment. One Design sailing emphasizes sailing skills when one races.
13. Rhumb Line: The Rhumb Line is the most direct line to your destination point, which when you are racing is the next mark. Rhumb lines take into account the curvature of the earth.
14. Right of Way: Right of way involves sailboat racing rules that dictate who has the right to sail in front of or near other sailboats. Right of way is very important because sailboats that have achieved right of way can sail in front of other sailboats or gain a tactical racing advantage over other sailing competitors.
15. Starboard Tack: If one is beating close to the wind and the wind is coming over the right side of the boat, one is on a starboard tack. The sails are on the left or port side of the boat.
16. Wind Direction: Wind direction is the direction that the wind is blowing. Because wind directions are continually changing, understanding and computing wind direction is a critical factor in sailboat racing.
A) Completive sailing has become a recognized international sport.
1. First international sailing competition originated in the 1800s with the America’s Cup.
2. One design boats originated in the 20th Century.
3. Use of geometry in sailing can be found in ancient times. More recently, sailing technology has relied on geometry to improve the technology of sailboat racing.
B) Race tactics and strategy have become increasingly important in one design racing.
1. Since “one design” boats are identical, sailing skills become the key factor in winning races.
2. Since “one design” boats technically all go the same speed, traveling less distances and obtaining “right of way” becomes very important.
3. Since sailboats must always sail at an angle to the wind (to avoid being head-to-wind), a sail boat racer can never sail directly to a mark. Therefore, determining the most efficient angles to sail at to sail the least distance to the mark with the most wind becomes critical.
C) A sailor cannot sail directly into the wind, the boat will be “in irons,” and the sails will flap and flog. A sailor needs to avoid this “no sail zone.” A boat can only sail at an angle to the wind. Etchells typically must sail at least 25 degrees “off the wind.”
Sailing toward the wind is called “beating.” If you sail as close to the wind as you can without being in irons, than you are tacking. If the wind is coming over the left side of the boat, it is called a “port tack.” If the wind is coming over the right side of the boat, it is called a “starboard tack.”
A sailor tacks to port and starboard as he beats windward toward a destination, which typically in a race is a mark.
D) There are three interrelated calculations that are made on every tack.
1. You need to look at your compass and identify the compass reading to the mark. This creates your first geometric vector, which is known as the “rhumb line.” Technically, this term relates to ocean sailing and accounts for the curvature of the Earth, but in sailboat racing on Puget Sound or Lake Washington it means a direct compass bearing on the mark. In perfect conditions, the “rhumb line” is the same as the “lay line,” which is the course on which a boat sailing as close to the wind as it can without going into irons and can make the mark without altering course. Unfortunately, the wind rarely cooperates with this geometric convergence, so sailing up wind means you have to tack a lot. To determine the “rhumb line” you can use a variety of different electronic devices including binoculars with magnetic readings, GPS navigational equipment, and different types of compasses including, the electronic compass shown below. Mark Brink and my father, the experts I relied upon, used a Tacktick Micro Compass.
2. After you calculate the “rhumb line” you then calculate the wind direction. You then make your first set of calculations by determining whether you should be on starboard or port tack as you attempt to most quickly and efficiently sail to the mark. Maintaining the most direct course to the mark using a “close-hauled tack” is a critical factor in winning sailboat races.
3. Understanding wind angles and comparing them to the angle to the mark can determine the most effective angle to sail the boat. As the boat sails on a close-hauled tack, Mark Brink and my father took a Tacktick Compass reading for the direction of each close-hauled tack. In Etchells, typically a close-hauled tack can go no closer than 25 degrees to the wind. The calculation is as follows
X= Rhumb Line
Y= Wind Direction
To determine the close-hauled starboard tack:
Starboard Tack: Y-25 degrees
To determine the close-hauled port tack:
Port Tack: Y+25 degrees
4. Since wind direction, current, and the location of other boats continually changes on the course, the efficient and effective use of geometry is critical. Wind changes continually so the calculation of whether one should be on port tack or starboard tack as you try to stay as close toward the rhumb line happens continuously. In the drawing below the oscillation of the wind ten degrees will tell the sailor whether he should be on the port tack or the starboard tack.
Assuming that the wind direction was at 190 degrees (south southwest) then the calculation would be:
Starboard Tack: Y-25 degrees 190 = Y-25: Y= 165
Port Tack: Y+25 degrees 190= Y+25: Y= 215
Assuming that the mark was at 180 degrees (the Rhumb line or X), then the boat sailing against a wind of 190 degrees would want to be on the starboard tack because the calculation on the starboard tack would only be a 15 degree angle off the Rhumb Line whereas the port tack would be an angle of 35 degree angle.
X – 165 = 180-165=15
X-215= 180-215 = -35
With a twenty degree wind shift to port, the wind would be coming from 170 degrees, or south southeast.
The calculation to determine the close-hauled starboard tack would be:
Starboard Tack: 170 = Y-25: Y= 145
The calculation to determine the close-hauled port tack would be:
Port Tack: 170 = Y+25: Y= 195
Assuming that the wind changes 20 degrees to port or to 1780 degrees, then you would make a close-hauled tack to port to 195 degrees because the calculation on the close-hauled tack would only be a 15 degree angle off the Rhumb Line whereas the starboard tack would be an angle of 35 degree angle.
X – 145 = 170-145=35
X – 195= 170-195 = -15
E) Understanding geometry, particularly the Pythagorean Theorem, is essential to winning races. The formula for the Pythagorean Theorem is:
A2 + B2 = C2
This formula is used the most frequently to determine the distance to the mark based on the vectors that and angles that are determined each time that a boat tacks. In short, Puget Sound or Lake Washington races, the distances are short and wind and current are more important in making tactical sailing decisions. However, in long distance races such as the Victoria to Maui race that my father and Mark Brink completed this summer, the use of the Pythagorean Theorem, in conjunction with rhumb lines and weather information, become critically important.
Whats the best way off the line? Which way do you go? Find out all this and more in our article on starting tactics.
In our first article on Racing, we went over an introduction to all things racing – now we plan to expand on it. These articles still won’t be as detailed as they could be – we have yet to cover the rules in detail on Caution Water, and the rules enter into every part of racing – we will cover basic rules, but will probably come back to visit advanced rules at a later date.
When first getting into racing, you’d be forgiven for thinking it’s a case of get to the start line, race, finish – it’s nowhere near that simple, and the tactics and preparation start at the start line. But first, some basic terms.
Most start lines have a pin end, and a committee or starting boat end. The pin end is typically a buoy or fixed point on the water, and the committee boat end is a safety boat of some sort that is monitoring the race start – the race may be started from this boat, or from a point on land, depending on the venue – obviously if a race is happening just off the coast, then the officers running the race will do it from safety boats, whereas if it’s on a lake, they may do it from the warmth of a starters building or the clubhouse if it’s next to the water.
An alternative method employed by some clubs is to use a transit system – two objects are placed on the side of the water, and the boats involved have to make a transit between the two objects as shown in the picture below – this is a transit between two points, and indicates the start line. This is typically used at smaller clubs.
Types of Start
There are two types of start – a line start, and a gate start. The line start is the most common, and this is the type that involves a pin end and committee boat end. These two ends are placed a certain distance apart (which depends on how many boats are taking part, the size of the venue etc), and when the whistle blows, or the flag signals change indicating the start of the race, all of the boats have to pass between these two ends of the line to start the race.
The second type of start, the gate start, is not as common. For this type of start, a powerboat travels along the length of the start line in front of the boats racing, and as the powerboat passes in front of you, you are allowed to start racing. Downsides to this include mostly the chance of hitting one of the starting boats, which can give you a penalty – plus you get disrupted water from the wake off the powerboat, which can be especially bad news on days without much wind as what little shape is in the sails can be knocked out by the waves you are sailing through.
Line starts can have their disadvantages too – for particularly large events with over a hundred boats taking part (several of the National Optimist races in the last few years have had over 300 entrants!), the start line can be especially long, and the conditions can vary along the length of the line, which makes your position even more tactical. We’ll see more on this in a moment, when we talk about line bias.
How is the race started?
Races are usually started with a series of signals, either noise signals (a whistle or horn) at a set of intervals, or a series of flags are raised and lowered at set intervals, typically 5 minutes, then 4 minutes, then 1 minute, then race start. We’ll look more at starting signals in the next article of this series.
So it doesn’t matter which end of the line you start on, right? Wrong!
Depending on how the course is laid out, if you start on the left hand side of the line as in the diagram below, you are already closer to the first windward mark, and can sail a shorter distance than if you start on the right hand side of the start line. This should factor heavily into your tactics for deciding where to start on the start line. The race start line is rarely at a true right angle to the first mark – that is the windward mark is directly upwind of the start line as shown, and usually you will find one end is closer to the mark than the other – and the longer the start line is, the greater this advantage can be. This is known as line bias.
However, consider this – if you start on the port end of a biased start line, and say you are two boat lengths closer to the mark, if the wind is stronger and more favourable on the other end of the start line, people starting the other end will be sailing into stronger wind, with more speed. Therefore, is is better to start at the end of the line nearest the wind (i.e. if the wind is coming from the left side, start at the port end of the line).
A good race officer will “bias” the start line by a small amount, say 5 degrees, that is, they will shift one end of the start line upwind slightly, and make the start line angled in relation to the first mark, rather than at right angles to it, as shown. This introduces slightly more in the way of tactical thinking required while you’re battling for position on the start line.
Preferred side of the course
But, it’s not just about where you start! There is usually a preferred side of the course. One of the most important things to do during pre-race preparation is to get out on the race course and sail it a few times before the race starts – this way you can figure out which side of the course is the better side to sail on.
In the diagram below, the purple boat has picked the side of the course which has a shorter route to the buoy – however, there is less wind on this side of the course. The red boat meanwhile has picked the other side of the course, which while slightly further to the first mark (buoy), has considerably more wind than the other side of the course – therefore the red boat gets to the first mark first.
Why would one side of the course be better than the other? There are various reasons why one side of the course may be better to sail on – it may have stronger wind or more gusts, it may have less currents or tide, or more room to manoevre meaning fewer tacks. Smaller lakes can often be surrounded by trees that can make wind patterns very shifty and hard to identify or monitor, leading to wildly varying wind conditions over the lake (on our lake, in one 10 x 10 metre spot in the middle the wind often does a complete 180 turnaround).
Features of the land can also cause differences in wind, particularly around headlands – we’ll cover more on this in a later article. They don’t have to be obvious either – when we were sailing in Greece, we were in a semi-sheltered bay, with a pretty consistent wind over the entire bay, yet even sailing in Lasers in a steady Force 2 morning breeze every race there was a faster side of the course to sail on – not alway faster by much, but you could definitely tell. All of these can mean one side of the course is better to sail on than the other.
Unfortunately, the only way to determine which side is the best side (apart from visually identifying key features such as headlands, or looking up maps that show tides and currents) is to get out on the course first thing, and find out for yourself.
But why is this important for start line tactics? We’re talking about the rest of the race, aren’t we? Yes, but the side of the course you want to sail on helps decide which end of the start line you wish to sail on. If you are going to come off the start line on port tack, then immediately tack onto starboard, you may be best starting at the port end of the start line, otherwise you may have lots of boats heading straight at you – you may well have right of way, but there are going to be a lot of angry sailors on those boats, some with bowsprits they can poke you with!
Once the whistle or flags go – you’re off… that is, unless you did something wrong. If you were over the start line at the start of the race, this is known as OCS (On Course Side at start), and depending on the race rules, you can either be recalled back, in which case you have to sail back behind the start line, and cross it again (i.e. restart) – if you don’t you will be disqualified even if you completed the race, or you can be disqualified straight away. Generally speaking, you are recalled to recross the start line. Sometimes if too many boats are over the start line before the race starts, the entire race start will be called off, and all the boats will start the countdown to the start again.
Believe it or not, this is again only an introduction to starting tactics – there are all kinds of detailed rules telling you how you can find a spot on the start line, who you’re allowed to force out of the way and so on, but for now, if you’ve read through what’s written above, you’ll be better off than a lot of smaller club sailors!
Are you looking to improve your upwind sailing tactics? Below are several ideas to help you master the upwind legs. First, you have to know what the wind is doing. Is it oscillating back and forth, or is it in the midst of a persistent shift?
This question needs to be answered before you start, because it will help determine your upwind strategy and thus your starting strategy. If you don’t know what the wind is doing, try to sail up the middle of the course. However, one side of the course or the other will almost always pay out more than the middle, so try to determine what the wind is doing and thus determine which side of the course you want to sail on.
If the wind is in a persistent shift, you’ll want to sail towards the shift after the start to get the most benefit from it. For example, if the breeze is slowly shifting to the right, you’ll want to head to the right after the start. Although you’ll be slowly headed, when you tack and head back towards the middle, you’ll get a persistent lift towards the mark. If instead you continued away from the persistent right shift towards the left side of the course, you may miss the benefits of the big shift or have your position hurt by persistent headers!
Now, if the wind is oscillating back and forth and is not experiencing a persistent shift, you’ll want to be sure that you are always sailing on the lifted tack with each shift. If you don’t tack on the headers, you’ll have to sail more distance to get to the mark than the people who sail on the lifts and tack on the headers. Here’s another thought when playing shifts. Although it can be difficult to duck another boat when you have the right of way, it occasionally makes sense. For example, suppose that you’re sailing the lifted tack on starboard tack, and a port-tacker, sailing on the headed tack, is on a collision course. You could keep going and shout starboard at the top of your lungs, but you’re taking a risk: what if the port-tack boat lee-bows you, and forces you to tack to port to get out of their bad air? You’d be sailing on the headed tack, and they’d be sailing the lifted tack. The best solution in this instance would be to waive the port-tacker ahead and duck them, even though you’ve got the right-of-way. You may lose a half boatlength of distance from the duck, but they’re sailing on the headed tack and you’re on the lifted tack – you’ll come out ahead in the end.
In light air, let your strategy try to maximize the time that you sail in the puffs, and don’t try to sail for windshifts (unless they’re drastic shifts). The reason for this technique is straightforward: if the breeze is very light, a puff may double the wind’s velocity. As the wind speed increases, you should change your strategy from playing the puffs to playing the shifts.
A similar rule of thumb applies to sailing in bad air. Of course, you should avoid sailing in someone’s bad air. However, in light air, you are affected much more than you would be in heavy air because the wind pressure that you feel could be cut in half. In heavier air, bad air has less affect on you.
Try not to tack too often. In general, a good roll-tack will cost you 2-3 boatlengths of lost distance as the boat accelerates up to full speed again. A bad tack can cost you 5+ boatlengths of lost distance. While we’re on the subject, the rules stipulate that you can’t come out of a tack faster than you started it. So, it’s illegal for you to keep roll-tacking your boat upwind to keep moving when there’s no breeze.
Written by Neil Ashton. Posted in Sail Racing Tactics.
Have you ever been sailing in a steady breeze with no shifts and realized that a competitor with equal speed, sailing on the other side of the course, has made big gains on you?
The answer could be that they were sailing in less adverse current than you.
Using Current to your Advantage
When current plays a big factor where you’re sailing, you always want to be sure to be sailing where the current helps you out the most or does the least amount of damage. Current tends to flow faster in deeper water than it does in shallow water. If you are sailing towards the flow of current, you are sailing in adverse current. Your goal, therefore, is to sail in areas where the current is flowing against your direction of travel at the slowest speeds. In many cases, this will be where the water is shallowest.
However, if you are sailing in the same direction as the current’s direction of flow, you want to sail where the current is flowing the fastest in order to get the most benefit of it carrying you towards your destination.
I can remember a high school regatta sailed at the Fort Schuyler. The Academy is located on a river, and on the day of the regatta, the wind was flowing down the river in the same direction as the current. On the upwind legs, we sailed in this adverse current, and downwind the current helped us out. After the start, I tacked to port and headed for shore where there was less adverse current going against me. I then tacked to starboard when I thought I was at the layline. Most of my competitors had headed up the middle of the course where the adverse current was strongest trying to play the wind shifts. By the time we got to the windward mark, we had a healthy lead on everyone, due to playing the current to our advantage.
Downwind, we headed for the middle of the river where the current was fastest to help us get to the leeward mark as quickly as possible. We rounded, and sailed up the shore again to the finish.
The moral of the story? When the current is going against where you are trying to go, sail in the slowest flowing water as possible. If the water is flowing in the same direction that you are trying to go, you’ll get there faster if you sail where the current flows the fastest.