#downwind trim

Quantum Sails’ Dave Flynn breaks down key factors to take into consideration when sailing downwind to help get your angles, jibes, and speed up to snuff. With some practice and keeping track of what works in different breeze ranges, you’ll be ripping downwind in no time!

WHAT ANGLE SHOULD I SAIL AT DOWNWIND?

It can be useful to divide sailing downwind into three modes: under 10 knots true, 10-14, and over 14.

If you own a relatively standard mono-hull, the magic true wind angle is around 140 degrees in 10 knots of wind or less. In 10-14 the optimum angle quickly becomes broader, somewhere in between 140 and 155 degrees true wind angle. Once there is more than 14 knots of breeze, you should be sailing as deep as you can with control. The only exception to the rule is if your boat has a very high horsepower-to-weight ratio, in which case you may sail slightly tighter angles on average. In 14+ knots it will actually pay to head back up into the low 140s. If your boat is light enough, it will begin to plane and surf in this much breeze.

What if you don’t have instruments capable of providing true wind angle? Notice, apparent wind angle was never referenced. This is because the optimum apparent wind angle changes rapidly with relatively small changes in wind speed.  A typical displacement mono-hull will see the optimum apparent wind angle range from 90 to 130 degrees as the velocity increases from 4 to 10 knots. This makes the apparent wind angle simply too volatile to be useful. The true wind angle remains virtually constant over this same range. Hence, it’s power.