A Coastal Race Primer
A Coastal Race Primer
Shorter point-to-point races require a different level of preparation and a more assertive approach to tackling the course. "Strategy" from our May 2012 issue.
Rule No. 4: Beware the night trap
By definition, a coastal race is near a shoreline where geographic wind shifts—bending and acceleration (or deceleration) are commonplace. Some of this can be predictable, for example when the wind parallels a mountainous coastline, the headlands and points will likely have good “puff” while the bays in between can be lighter. So it pays to look at the chart and come up with a theory on how the geography will affect the wind. But always keep an open mind; your theory may not pan out. The bottom line is you should expect changes to the wind as you get closer or farther from the land, and you should be tactically sensitive to these changes. For example, beating along a coastline at night, be extra vigilant for wind changes.
If the wind speed starts dropping as you sail on the tack converging with the land, for example, then tack back out and see if it increases again. If so, you may have discovered a common coastal trap: At night the wind is often lighter closer to shore than offshore. A caveat to that rule is in an offshore wind condition where sometimes the best puffs are right in close to shore, especially if the coastline has some elevation inland. Air likes to sink at night and “drain” back to the coast.
In the daylight hours, a lot of our racing takes place in sea breeze conditions. As with many different local and mesoscale wind conditions, it pays to have more than a rudimentary understanding of meteorological principals and the dynamics of these wind features. If you can, through study before the race, try to have a feel for how far offshore the sea breeze will exist, and how the gradient wind will be filling in beyond its reach. Remember that at the outer edge of this band, the wind can be quite light as the local thermal wind transitions back to the gradient wind. Depending on the time of day and stage of the sea breeze cycle, you will likely want to avoid this transition zone. And, especially in the building phase of the sea breeze, the wind may be stronger near the shore.
Rule No. 5: Don’t bum the rhumb
Unlike offshore races where “flyers” are more commonplace because of the wide playing field, a coastal race requires real rhumbline discipline. Shorter legs mean there’s less chance that a new wind is going to develop in time to save the guy who sailed all that extra distance to get far offshore. If the leg is a “fetch,” the helmsman and trimmers should be really cognizant of the bearing to the next waypoint and have a very good reason for deviating more than 5 or 10 degrees from rhumbline. A racecourse with more turning marks provides more opportunity to gain by sailing the shortest distance and avoiding suffering into a turn at a “bad” angle.
A helmsman trying to minimize extra distance on a reach should also be aware of the difference between heading and course over ground (compass error, leeway, and current all come into play here) so that the desired course can be achieved. And just as it’s a near given that the wind will change near the shore, so too will the current. Again, studying the chart and bottom contours may help you come up with a theory on how the current will run. Compressed against a shore, an “along-shore” flow can actually accelerate near the coast. This is contrary to the general notion that current runs stronger in deep water. It may be that you have to get quite close to the beach before you see any diminishing of the current flow. Again, be aware that there will be differences and watch for them (on your instruments and on buoys or fishing pots) as you are sailing along the coast.
The bottom line is that coastal races require an organized sailing team that leaves little extra distance or extra time on the racecourse. The afterguard must be highly observant and open minded to changes in conditions brought on by the proximity to the shoreline. Even if the wind shifts in an unexpected fashion, the teams that are watching and waiting for changes will be able to better capitalize.