12
J/105 Tuning Guide
Solutions for today’s sailors
it will keep the main pressurized as well
as opening the slot between it and the
spinnaker to get the air flowing over it
faster. The main trimmer can easily feel
if the main is pressurized by the pull on
the sheet. Ease the main out slowly as
the pressure on the sheet builds as the
spinnaker is eased.
Moderate Air Sailing (9-12 knots TWS)
In moderate air, there is a wide range
where you can sail. Lower is best as long
as you can maintain your speed. The tack
line is eased 0.6-0.9 (2-3’) off the sprit. The
same principles apply to steering as in light
air. Once the boat feels well pressured, the
crew should move to the windward side
to help rotate the spinnaker. In this range
the crew should be very active moving to
weather when you head down in the puffs
and back to leeward when you head up in
the lulls.
Heavy Air Sailing (12+ knots TWS)
In over 12 knots, the boat is well pressured
up going downwind. At this point you want
to sail as low as possible most of the time.
There will almost always be good pressure
on the sheet but when you sail too low,
the sail will become blanketed behind the
main and collapse. The sheet is well eased
to get as much of the sail out from behind
the main as possible. The crew should be
to windward at all times. Heel the boat to
windward by as much as 10 degrees. The
vang should be set so the top batten is
parallel to the boom.
DOWNWIND NOTES
Good coordination between the trimmer
and helmsman will result in very
subtle changes in the sheet. A properly
coordinated team will only adjust the sheet
by a couple of feet. If you find yourself
constantly trimming and easing more
than 3 feet of sheet than your coordination
should be improved. Be careful not to try to
sail too low and collapse the spinnaker. A
collapse will result in around a three-boat
length loss!