Mariner’s Web

Sail Trim – It’s Kind of Like Jazz

There is an old adage that “life begins” at the age of 40 – and I tend to agree since that is about when I got my first sailboat and also became an aficionado of jazz music.  I just gave a sail trim seminar to around 30 people associated with our Boulder Valley Sail group.  The feedback was good but I had no idea how hard it would be to pack it into two hours.  It occurred to me during my preparation that sail trim is kind of like jazz:

• Expressive (sail shape)
• Improvisation
  • Making & creating in the (lifting) moment
  • Responsive to the stimulus of one’s immediate environment (puffs, lulls, shifts, waves)
• Syncopation
  • Disturbance or interruption of regular flow (keel, sail plan, angle of attack)
  • Unexpected deviations and unequal durations (s-turns, balance,trim)

A creative description of a sail plan may go something like this: Flexible wings flying in a twisted flowfield, interacting in the presense of one another. I conjur up an image of Pigpen of the Peanuts cartoons who is always surrounded by a dirt cloud. Instead of moving along in a cloud of dust a sailboat moves along in a cloud of disturbed air with upwash, downwash, and vortex’.  The airfoils from a sailboat generate a small weather system of high and low pressures with the assocated pressure gradient forces – hopefully creating lift and speeding you along. Camber and angle of attack are controlled along a span in order to produce lift. Stall and luffing provide the upper and lower limits of useful angle of attack.  Let it be a rule of thumb when sailing in the proximity of other boats – seek the clear air and turn on the jazz.