sailboat seamanship 191
- Move the sheet block forward or aft on its track until the mid-luff point, the
clew, the sheet, and the block describe a single straight line. You have found
the neutral block position. - Mark this position on both genoa tracks. Repeat this procedure on trunk-
mounted jib tracks (short strips of track mounted on the coachroof ) for a
smaller headsail if your boat has them. - Position both sheet lead blocks at the neutral position. Trim the headsail
leech as shown above according to wind conditions. Always try to match
the headsail and mainsail leech curves aft er trimming. Take care not to
overtrim the headsail, which will cause the main to backwind, or bubble
along its luff.
Medium-air trim; lead blocks in neutral position. In 6 to 10 knots of wind, keep
the blocks at the neutral position. Th is evenly distributes foot and leech tension.
Light-air position; lead blocks forward of neutral position (power up).
In light air, move the blocks forward. Th is places less tension on the foot
and more on the leech, resulting in a fuller sail and more forward drive
to punch through a chop.
Heavy-air position; lead blocks aft of neutral position (depower). As
winds increase, start moving the blocks aft. Th is tensions the foot more
than the leech, resulting in a fl atter sail with more leech twist aloft.
SEA-CRET TIP
X Make sheet lead block changes one track hole at a time. Move
one stop and check your speed. Repeat until you are satisfi ed.
X Always move both lead blocks together. Set the working sheet
lead block; then match the lazy sheet lead block. If the working
sheet block is under too much tension to be moved, adjust the
lazy sheet lead block, then tack and adjust the former working
block, which is now lazy. If you have a furling headsail, you might
need to reposition the blocks after you partially furl the sail to a
reefed position.Take Note of Your Boat after Trimming Your Sails
After you trim any sail, make sure to check these three things:
Did the boat accelerate or decelerate? Watch the relative motion of objects
(piers, boats) against the shoreline. In very light winds, observe your boatspeed
relative to your wake trail bubbles. Look astern and note if the bubbles appear to