UPWIND SAILING GUIDE

WindCondition Extremely light (drifting) 0-4 NORMAL CONDITIONS Extremely Heavy 22-30 Light 4-8 Moderate to Heavy 8-22 Trim Goal Keep moving by reducing drag Accelerate Head Closer to Wind Foward motion through rough sea Trim Style Pointing Power Pointing Power Sail Shape Smooth Water Rough Water Overall Flat Medium Full Med. Flat Medium Entry Flat Flat Full Medium Med. Full Exit Med. Full Med. Flat Med. Full Medium Flat

Figure 7

Twist Maxium Medium Med. High Min. Med. Low Bottom 1/3 Flat Med. Flat Med. Full Medium Flat

Graph 1

(Graph #1)

Special situations for each trim style: Power Pointing

·acceleration ·when at max speed upwind·disturbed airflow·clean air·out of tacks·during gusts ·rough water·flat water·after hitting waves

Cross-cut panel layout.Panels are cut so thatshaded area is removed(broadseaming), whichgives depth to the sail.This graph shows how the power/pointing relationship changes as the wind increases. The left hand sideof the graph represents lightest wind. Moving across the pages show how trim should change as windspeed increases. Note how the trim in light air should be very different for smooth or rough water. Alsonote how, once you have heavy air (over 20 knots), the pure pointing mode must be modified slightly topower as the increasing windspeed will generate choppy seas.

Racing considerations

T

he racing sailor has to consider three other primary trim factors. They are : twist, angle ofentry and vertical distribution of depth. They may sound complex, but they are in fact quitesimple.The Grand Prix racer will tell you that there is a fourth critical factor: exit angle. In this bookletwe will avoid discussing exit angle because it’s difficult to do anything about the shape of theback third of the sail using only the controls on the boat. That’s really a question of entirely re- cutting the sail. The little that can be done to alter exit angle will be mentioned in the thirdpoint: vertical distirbution of depth.