LSC Crew Notes - August 13 , 2003

Information for Crew Involved in Racing with Members of the Lansing Sailing Club.

Crew Practices Dealing With Velocity headers
It was another beautiful evening on Lake Lansing yesterday and three boats full of crew took advantage. One of the boats focused on what to do when the wind velocity suddenly decreases and the sails luff. This condition is called a "Velocity Header". Understanding what is happening requires knowing about "Apparent Wind" - the main subject of this issue of "Crew Notes".

Apparent Wind
Imagine that you are straddling your bicycle getting ready for a nice ride on a beautiful morning. The road in front of you is straight and takes you north. As you stand there making final adjustments on your helmut, you realize that there is a mild wind of about 10 mph on the right side of your face. Since you are a sailor in addition to a bicyclist, it registers with you that the wind must be coming from the east (you are facing north and you feel the wind on your right side).

Now you begin to ride north. At first you are taking it easy, enjoying the scenery. A look at your speedometer tells you that you are traveling 10 mph. The wind direction seems to have changed however - it seems to be coming from a direction more in front of you. Curious, you put on the brakes and come to a stop. The wind is still coming from the east. So, what happened?

While you are standing still, you are feeling the "True Wind Direction". But once you begin to move, you feel the combination of nature's wind and the sensation of wind you create by moving. This combination is known as "Apparent Wind Direction".

You take off again. This time you go faster and faster. The faster you go, the more the wind seems to come from in front of you.

Another Example of Apparent Wind
You are getting ready to sail. Standing on the dock you realize the wind is still the 10 mph is was earlier when you took your bike ride. As you sail upwind, the wind feels stronger. You turn to go downwind and realize the wind feels almost calm.

Here is what is going on. As you go upwind, the wind is 10 mph and the boat is going 3 mph toward the wind. This combination is the "Apparent Wind Speed" and it feels like 13 mph. Going downwind, the wind is still 10 mph and the boat is still going 3 mph. However, the boat is now going in the same direction as the wind - and this "Apparent Wind Speed" combination feels like only 7 mph. The "Apparent Wind" is the wind you feel as you move.

So, Why is Knowing About Apparent Wind Important?
The more a crew team knows about apparent wind and how it affects the boat, the more effectively they can trim the sails and steer to gain maximum advantage. More on this in future issues. If you want to know more right now, head to www.sailnet.com/collections/articles/index.cfm?articleid=colgat003 with your internet browser and check out an article by Steve Colgate. While there check out some other other resources on sailnet's site.

Practice Tuesdays
Don't forget that we continue to practice on Tuesdays from 6 PM to sundown. The goal is to to provide a structured opportunity for crew and skippers to expand their sailing skills. It is helpful to email Pat Dolan, LSC's Crew Coordinator ahead of time to let him know you are coming. This will help assure sufficient boats will be available to accommodate those participating. You can just show up - but no guarantees on whether there will be a spot for you. Only lightning and very high winds keep us off the water. Assume we are practicing. If weather conditions are really bad, we have plenty of video to watch and "chalk talks" ready.