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post #1 of Old 11-25-2001 Thread Starter
Dobbs Davis
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Negotiating Leeward Gates

Ever come into a leeward mark rounding and find a wall of fiberglass with nowhere to go? This has been a common problem for popular one-design classes and large multi-class regattas where many entries of dissimilar size and speed try and spin around the same mark. To relieve this excess crowding and congestion at leeward mark roundings, the powers that be within race administration have devised the leeward gate. Itís an alternative method of turning the course upwind, and for several years now itís been gaining popularity among race organizers.

Overcrowding at leeward marks is one of the reasons that leeward gates were devised.

Simply put, the leeward gate consists of two marks positioned perpendicular to the wind and usually several boat lengths apart. By giving the fleet a choice in which mark to round, the crowding problems are usually reduced and racers can focus on getting settled in to the next leg of the course.

That's the good news; the bad news is that having a choice can make for indecision and last-second changes that can throw off the crew's plan for executing the right maneuvers to get around one or the other of the gate marks. And if the gate is not exactly perpendicular to the wind (which is often the case, since the wind does shift after all), then one mark of the gate will be favored over the other. Since a boat going through the gate is travelling downwind as well as upwind after the rounding, the bias between the favored and unfavored ends is twice the distance off of perpendicular to the wind. This makes finding the favored end an important task.

It's critical to fly the spinnaker for as long as possible, which often means getting rid of the spinnaker pole early and employing a "human pole" on the afterguy. Doing this will also allow you to jibe at the last minute to head for the other gate mark should that be the best option.
Staring downwind at a gate is rarely a good method for finding the favored end, particularly in traffic, so it's useful to use other means. One I like is to do some homework before the race starts by sailing by the gate (if it has already been set) and getting a compass bearing on the axis between the marks. Just as in a starting line, if the wind is 90 degrees to that bearing, the gate is square, and if not, then the favored side can be determined. Even if you don't exactly know what the wind is direction while going downwind, by keeping track of your jibe angles and knowing that gate bearing you can often get a relative sense of which end might be favored regarding the latest wind shift.

While the tactician mulls over these geometric nuances, the crew must prepare for whatever decision is made while still pushing the boat hard to get to the mark. As with any rounding, flying the spinnaker as long as possible is ideal, but you must be ready to douse it quickly and get the jib and main set up for going upwind. The helmsman may have to perform some intricate ballet to deal with traffic issues, so the crew should be aware of this and ready to adjust if necessary at the last minute.

For example, if the favored end looks too crowded to get to without having to endure a lot of bad air after the rounding, it may be faster to sail the extra distance to go the other end. The crew therefore has to be flexible at being able to hoist the jib and continue to fly the spinnaker despite the change in gameplan. Flying the spinnaker without the pole is therefore an important skill that the crew needs to master. Obviously, on a boat with a conventional spinnaker pole, once you remove that from the program it becomes much easier to get the kite down.

As the boat begins its turn at the leeward mark, having the jib more eased than the mainsail will help the person on the helm bring the boat up to a closehauled course.

The best way to do this is to hoist the jib early and trip the spinnaker guy out of the pole; lower the pole off the mast and to the deck. When doing this, the weather clew of the spinnaker will no longer have the pole to project the sail away from the rest of the sail plan, so remember to adjust for this by pulling the guy or lazy sheet back and ease the sheet a little to compensate. The jib should only be loosely sheeted, if at all, particularly if the spinnaker exits the mast near the jib halyard exit box. The disturbed airflow around the jib will stall the flow into the spinnaker and likely cause it to collapse, especially in light air, and your boat will slow down just when you were hoping to maintain your speed into the mark rounding.

On all but the biggest boats, the douse should always be on the port side, since that's the side the spinnaker will most likely be set from during the next weather mark rounding. This will mean executing a weather douse for port roundings around the left side mark, or a leeward douse for starboard roundings around the right side mark. If coming into either mark involves a jibe turn, always specify which side of the boat youíll be bringing the spinnaker in on instead of saying "weather douse" or "leeward douse," since that meaning will obviously change in the turn and can be a possible source of confusion.

As with any leeward rounding, make sure the upwind sail controls are set for the prevailing conditions; the outhaul, cunningham, backstay, jibsheet lead, jib halyard, and jib inhaul (if your boat has one) should all be set in advance of approaching the mark. In light or choppy conditions, err on having slightly more powerful shapes in these sails in order to be able to accelerate away from the mark, since the air is usually lighter and more disturbed in the vicinity of the gate due to the presence of other boats.

Judicious trimming on the headsail during a leeward mark rounding means bringing it in gradually, in concert with the steering and the trim of the mainsail.
Once the spinnaker is down and the sails are being trimmed to go around the mark, remember to focus on getting the main in fast and to hesitate a little on the jib. The reason for this is that in a tight tactical rounding, the main trim will give the boat the height it needs to have a strong weather position. Trimming the jib in too fast not only stalls the flow over the main, but causes the boat to bear off from that weather position and may allow a trailing boat a hole into which it can wedge its bow.

Use of these techniques and a little practice will help de-mystify gate roundings, and give you and your team more confidence and flexibility in negotiating any leeward mark rounding, whether its a gate or a single mark.

Suggested Reading:

Handling Leeward Gates by Brad Read

Making Mark Roundings Work for You by Dan Dickison

Heavy Air Racing Techniques by Dobbs Davis

Buying Guide: Spinnaker Poles

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