Find The Favored Side
This week J World Annapolis coach Buddy David shares his insights into finding the “favored side” of the race course. Buddy and his team are leading all J World boats this series and determining where the strategic advantage lies on the race course is something all racers must identify. So Buddy, tell us how you do it!
Favored Side of the Course
Picture this scene: You are standing around the docks post-race discussing the day’s triumphs and follies with other crews and someone states the profound wisdom “well you just had to be on the favored side for the first upwind”. Now everyone else is nodding in agreement “yes the (right or left) was way favored”. Even though this apparently universal truth remains a mystery to you, you find yourself nodding your head in agreement afraid to admit your ignorance. I will let you in on a little secret that you are in good company. One of the many challenges of sailboat racing is deciding where to go and when. My first bit of advice is to never be afraid to ask others; most sailors love to share his or her knowledge because they are good natured or because your admiration strokes their ego. Either way is a win-win.
Two distinct but related skills are (1) identifying the favored side and (2) understanding what is causing that side to be favored. Personally I find the second to be far more difficult. An import item of note is that the favored side may vary as you head upwind. For instance the right side may be favored near the start line, then the left side favored halfway up the course and finally the right is again favored at the top.
A short cut to identifying out the favored side is by simply watching others. Watch a preceding fleet and pay attention to which boats go right, left, or sail up the center then see who is ahead the next time boats converge. This is straight forward and while you may not know why, if you emulate their routes you will find yourself finishing in the top half of your fleet. Another method for identifying the favored side is to sail upwind with another boat of equal speed and pointing ability prior to the race. Sail on opposite tacks so one boat is heading left while the other heads right and observe who has gained position each time you cross tacks. If one side is consistently favored your lead will change each time you meet again. Using observation alone it is possible to recognize trends and develop your own rules of thumb for a given venue however this is really a reactionary approach. The next step is to understand all of the contributing factors so you can start to predict the favored side.
So the next step in your strategy education is recognizing the factors at play. Wind speed, current strength and direction, wave patterns, traffic, obstructions and last but far from least the wind direction.
Wind strength is pretty straightforward; sailboats need wind and more wind equals more speed. Figure 1 depicts two boats sailing upwind, the green track sails through higher wind and sails a greater distance in the same amount of time.
Current affects the speed and direction of our boats and is important to consider when finding the favored side of a race course. Current generally flows faster in deeper water so if we are sailing against the current we want to use the shallower side of the course and conversely we want to be in deeper water when sailing with the current. Figure 2 represents two boats sailing upwind against the current. The two tracks are equal in length however the red track represents a higher angle traveled upwind.
If you are sailing across the current on an upwind course sailing toward the up-current side of the course will increase your apparent wind and push you toward the center of the course thus acting as a lift. In figure 3 the two boats sail the same distance however the green track is lifted towards the mark while the red track is deflected away from the mark.
Traffic which may consist of other fleets, leaders of your fleet or non-racing boats can impact your wind and/or force you to sail a longer distance around them. If you find yourself sailing on port through a parade of boats on starboard under spinnaker you are in dirty air and dodging right-of-way traffic (and preceding fleets are usually larger boats which mean big wind shadows). Obstructions present both opportunities and pitfalls. With sound tactics and boat handling skills you can use obstructions to protect your clean air and force competitors to sail longer distances. A lack of either tactics or great boat handling will leave you with the short end of the stick.
Wind direction is also pretty easy to wrap our collective brains around, if the wind shifts to the right our course is shifted to the right whether we are on a close hauled port or starboard tack. When a shift helps us sail further up the course it is a lift and when a shift forces us to sail across rather than up the course it is a knock. So we try to maximize the time we spend sailing in a lift.
The wind direction can vary with time or vary according to a given position on the race course. The three primary types of shifts are: An oscillating breeze, a clocking breeze, or geographic shift.
An oscillating breeze varies direction over time, shifting right for a while, and left for a while and so on. In figure 4 the green boat has recognized the wind pattern as oscillating (either through forecasts and/or first-hand observations before the race) and knows to sail on the tack which is lifted. Any time the boat is sailing a course which deviates more than 45 degrees from the bearing from the start line to the windward mark, the boat is sailing in a knock and should tack.
A clocking breeze (also known as a persistent shift) is a wind shift that only changes in one direction over time. Figure 5 depicts the green boat anticipating the shift from the right and heads to the right side of the course early which places the green boat closer to the windward mark as the shift progresses further right.
This last possibility, the geographic shift is where the wind direction varies not with time but with position across the course. I often refer to this as a “bend in the wind” (I searched the internet to see if anyone else was using this terminology and only ended up with the forecast for Bend, Oregon). For instance at any given time the wind direction at the start line is 345 degrees, halfway up the course the wind is 0 degrees and at the top of the course 15 degrees. This stagnant variation can be “C” or “S” shaped with one or multiple bends to it and is most often a result of land masses funneling and turning the wind and therefore often encountered sailing inshore. Sailors often fail to recognize this situation and attribute the variation to oscillation or clocking because as they travel up the course there are two concurrently changing variables: time and their position. As the racer reaches the top of the course they notice that the wind direction is changed from what they experienced at the start line but fail to consider that the wind may have been blowing from a different direction at the top of the course before the race even started. This confusion can be avoided by thoroughly surveying the race course and making good notes prior to the start. Geographic shift are more likely to be encountered in inland and near shore racing however the same phenomenon can be found on offshore courses where no obvious land mass influences. Cloud formations and converging weather systems can cause a geographic shift.
I use one of three methods to determine what the wind is doing over time and position, the first is to sail around the course noting the wind direction at 9 positions around the course: Left, center, and right at the top, middle, and bottom of the course. Write down the wind strength and direction at these locations and repeat two times and you will have the data to recognize trends. A boat with mast head instruments makes this method more effective. I like to depict the results using laminated charts and dry erase markers for a nice visual result. A less precise method that requires less time is observing multiple boats sailing around the course and estimate their heading, this method works best on short courses. A third method is to simply start at the top of the course sail on a run wing on wing and track your heading. Do this a couple of times and you will have a good idea of variations are a result of time or position. If your results are the same each time, you can expect to encounter the same during the race.
So now that you have recognized the factors you need to evaluate how the compliment or negate each other and what is the result. This is the hard part. In some cases a couple of factors are insignificant (i.e. slack tide or steady breeze) and you can recognize one dominate factor. Other times all of the factors are in play and working against each other. Draw your best conclusion and then go out and test it. You will either get it right or wrong but you won’t learn unless you are paying attention.