Pre Start

Undoubtedly one of the most useful tools you can have on your raceboat. At the bare minimum you can use it to navigate and keep track of wind direction, but it's a powerful tactical tool as well. It's incredibly valuable for big-fleet racing on a long course in open water and is helpful on short courses to. What follows are just some ideas on how to get the most from it.

The compass's tactical usefulness begins on the sail out to the starting line. Every few minutes, luff and hold head to win until the compass heading stabilizes; write this number down as the wind direction (see examples in box). To get an accurate number, the boat must be flat and perfectly head to wind with the boom (or Windex, if you have one) lying straight down the centerline. Take these readings every few minutes to get an idea of how much and how often the wind is shifting. Once you're comfortable with the wind direction and you reach the starting area, sail upwind on both tacks and write down the headings you see on each tack. It may help to write down the range that you notice each time while sailing a particular tack, then turn that information in to a concise group of numbers. For example, sail upwind and tack every two minutes. At the end of 12 minutes you should have three sets of headings each for starboard and port. Then simply condense them to a prevailing range of numbers and identify what is the mean or average number on each tack. Part of the art is determining which headings you think are "real" and which numbers were influenced otherwise - either by a big puff, a bad wave, or driver inattention. By keeping track of the absolute high and absolute lows on each tack, as well you are able to put the "best" number (most favourable angle) first on your list and underlining would ensure ease of reference.

With the numbers for the upwind leg done, do the same for the downwind leg, sialing back to the starting area and recording numbers on each jibe. Again, write down the range of headings you see on both jibes. At this point it is a good idea to calculate your jibing angle.

Downwind bearings are trickier to get than upwind bearings because the angle you can sail is hugely affected by pressure. So it is important to be aware that the numbers you get will change as the breeze increases and decreases, especially in a lighter boat, and even more so with an asymmetric spinnaker. Recalibrate your angles when the change in velocity results in a big change in the angles that you are seeing and double check by gauging against the angles that other boats are sailing.

Once you have your upwind and downwind ranges, its time to make sense of the information accumulated. If the upwind numbers have been getting larger, then the wind is slowly shifting to the right. If the numbers are fluctuating up and down over some increment of time, then the wind is oscillating. An abrupt change in the headings could be a response to some weather activity, for instance, the sea breeze filling in. If one is short on time then one may have to prioritise. So knowing the headings on each tack is more useful throughout the race than knowing the head to wind numbers.

Shooting the Starting Line

When the line has been set, use the compass to determine which end is favoured. To do this, you must sail outside one end of the line, and then turn and reach along an imaginary extension of the line. Lining up the two ends of the start, sail along that line and write down the compass heading. For example, you sail outside the port end of the line and note the heading as 330 degrees. That would make the line "square" to a wind direction of 240 degrees (subtract 90 from the original bearing of line on port tack; add 90 degrees to bearing of line on starboard tack). If the breeze is to the right of 240 degrees, say 245, then the right hand of the line is favoured by 5 degrees. If the wind direction is 235, that means the left hand end of the line is favoured by 5 degrees.

Race committees often post the bearing to the first windward mark. If so, compare this with your head-to-wind numbers. If the committee's bearing is different than yours, either the two compasses are not exactly lined up or the race committee is observing or anticipating a wind direction from what you are currently seeing and have noted. Often they have a boat at the windward mark taking wind readings and if the breeze is slightly right at the top of the course, the race committee may place the first mark slightly to the right of the breeze as observed at the start line.

Continue to check head-to-wind numbers during the pre-start and if there is time, sail once more on both tacks, looking for any significant change in your range of headings. Apply the information you have collected into your plan for the first beat and the run by understanding whether the breeze has been oscillating back and forth or shifting in one direction. If the breeze has been progressively trending right or the race committee has set the mark right of the breeze you are seeing, you might anticipate more right shift and favour the right side of the course upwind and downwind. Besides wind direction, you should also factor in wind strength geographical factors, current and predicted weather into your plan.

What the Numbers Mean

Most simply, a lift while racing upwind helps you sail closer to the windward mark while a header does the opposite. Downwind, a header allows you to sail closer to the leeward mark. On starboard tack, if compass numbers increase, then you are on a lift. On port tack, smaller numbers are a lift. Write it down since it often helps to have "+ = lift" written on the boom or near the compass where it can be seen on starboard tack, and "- = lift" where it can be seen on port tack. If the breeze is a constant velocity across the course and all other factors (i.e. current, sea conditions) are the same, then you want to sail on the lifted tack upwind and the headed tack downwind. If you get more breeze, generally your boat will be able to point higher upwind or sail lower downwind. The breeze direction could be exactly the same, but the change in compass numbers may reflect a change in heading. Familiarity with the boat will help to determine the differences between a real shift and a change in wind pressure.

Talk about the numbers

In a doublehanded boat, the crew usually reads the compass and calls tactics upwind while the driver reads the compass and calls tactics downwind. As a tactician on a small keelboat it is important to ask the driver to just read the numbers aloud. It is unrealistic to expect the driver to keep track of the numbers - that's the tactician's job - but it saves the hassle of turning around and leaning in board to see the compass. When discussing the compass wile racing, talk about present heading in terms of how different it is from the mean, rather than talking about the actual numbers. For example, you're sailing on starboard at your mean number of 195 degrees. Your range on starboard is 200 to 190 degrees. You sail into a lift and the boat can head 5 degrees higher (200 degrees). The way to call it is "We are lifted 5 degrees." The next breeze allows you to head 5 degree higher still. So the call is, "We are lifted 10 degrees above mean." And perhaps one may also convey the information that it is the highest heading on the tack yet. So the current heading is always expressed in terms of its relation to the range - it just saves the others from doing the math.

Using the Compass downwind

As you approach the windward mark, the compass will help you decide which jibe you should choose immediately after rounding the mark. The deeper the angle your boat sails, the more critical this decision is. For instance, if your boat can sail fairly deep, you may sail the entire run on one jibe, so picking the correct jibe before the start of the leg is important. If when looking to windward, the wind is to the left of the rhumb line between the windward and leeward marks, starboard jibe will be favoured (in the absence of current). If the wind is to the right of the rhumb line, port will be favoured. You can figure this out by using your pre-start headings. When you luffed head to wind, was the mark directly upwind from the start, to the left or to the right? Has the breeze direction changed? If the breeze has not shifted and the mark was to the left of the breeze, then you will need to spend more time on port jibe downwind. If you boat sails so deep that a jibe will not be required, then you'll want to be able to jibe onto port immediately.

If the mark was directly upwind from the starting line and the wind is oscillating, then you will choose your jibe base on wind direction you're sailing right before you round the mark. If you approach the mark in a right shift - the numbers are higher on the compass on starboard tack - then you would be more inclined to jibe onto port, the neaded tack, downwind. If you're in a left shift - the lower numbers on starboard - then you can bear away and continue to starboard.

While sailing down the run, the compass is most useful if your boat jibes through wider angles. If this is the case, its often easier to see on the compass whether you're lifted or headed. Comparing your current heading to the range you established before the start will tell you if you are sailing the favoured jibe.

Downwind can also be a little trickier than upwind because you're traveling with the puffs and the onset and end of the puff may be more gradual than upwind and generally downwind sailing angles are more affected by velocity. It's easier to get confused by what changes in heading are caused by a windshift and what changes are caused by more or less breeze or by catching a good wave. Pay close attention to how much pressure you're sailing in and listen to the dialogue between the trimmer and the driver. Knowing the expected range of headings on each jibe can also help you with laylines. You will know when you are jibing through 90 degrees versus 60 degrees and can call the jibe to the mark accordingly.

For example, if you're sailing downwind in a sportboat or catamaran. You approach the weather mark in a left shift in an oscillating breeze. Your compass number on starboard is 190. Because it's a left shift, you decide to continue on the starboard header after rounding the windward mark. Your heading is 100. You sail for several minutes on starboard and the breeze eases. Your compass reading increases 5 degrees to 105 as the driver heads up in response to the trimmer's call that the spinnaker needs more pressure. In a few more boatlengths, you sail into new breeze and the compass reading increases another 5 degrees to 110. You are now lifted on starboard so we jibe onto the port tack. Once the boat settles down on the new jibe, your heading is 20 degrees.

Because you're jibing through an angle of 90 degrees, the layline will be 90 degrees abeam of our course as we approach the leeward mark. To judge a 90 degree angle you can often sight straight down the traveler or something that is perpendicular to the centerline. For other angles, it's good to have reference lines on the deck or know through which two points on your boat you sight to get a certain angle.

As you approach the leeward mark, again consider what phase the breeze is in by knowing where you are in your range. If the wind has been oscillating and you approach the mark on a port lift, you know that the breeze is in a left phase and that you will be lifted on port as you start going upwind. If you're headed on port, you'll think about taking onto the starboard lift after you round the leeward mark.

You can use the compass on all points of sail to see what the wind is doing, but its only telling you which direction the wind is from where you are. It can't tell you what's happening across the course or where there's more or less wind. For that, you still need to keep your head out of the boat.