A reminder that pinching doesn’t pay …

“Keep your head out of the boat!” That’s a phrase we’ve all heard from coaches in sailboat racing. It’s an important concept. In fact it will be one of our Rules to Sail By this year, but it is just as important to keep your head in [...]

It’s make or break time out on the racecourse, MARK RUSHALL explains how to get a flying start and what to do when things don’t go quite to plan.

J-24 Start Line Sag

  When the race officer sounds the starting signal for the Sunday race at Daydreamers YC, he can already see [...]

Lifted from WaveTrain, Charles Donne’s very literate sailing/boating blog.

(Photo by Fritz Guerin)

It wasn’t until I first sailed on a boat with an engine that I understood precisely what is most seductive about sailing. Any who have cursed the din of a motor while afloat will know exactly what [...]

From Sailing World for the last scheduled PTSA race of 2011.

by Steve Hunt

It’s easy to overcomplicate sailing, because it can be a pretty complex sport if you want it to be. That’s why, come race day, I stick to a few simple rules that keep me focused on the things [...]

Lifted from mysailing.com.au written by Dave Flynn of Quantum Sails.

The mainsail trimmer on Fez has depowered the main to cope with a sudden gust of wind. By including a more mainsail twist, the boat remains upright and sails faster.

Technically, twist is “the change in the angle of attack from the bottom of the sail to the top.”

Twist is necessitated by the changing speed of the wind, hence changing angle relative to the boat, as you move away from the water. The drag induced by the water slows the wind near the surface, shifting it relatively further forward by comparison with the faster flowing wind further aloft. This effect is exaggerated at lower wind speeds.

In the real world, it means that the leech of a sail must open up to some degree as we move from bottom to top.

In mechanical terms any time the aft end of the boom is allowed to rise, (easing the mainsheet or boomvang), twist is increased. The same length of fabric is now strung between two points that are closer together, so the leech of the sail opens up. Conversely, pull down on the clew and twist is reduced, closing off and rounding up the leech. A tight, round leech creates power and forces the boat to point, but can also cause airflow to stall, or overpower the boat (create too much helm and heel). A twisted leech profile promotes airflow in light air when it is hard to get air to stay attached, and in heavy air the flatter, more open sections depower the sail and help keep the boat on its feet.

On all boats, but particularly on the new breed of fast sailboats which often rely on bigger mainsails and smaller foretriangles, having the right amount of mainsail twist for the conditions is perhaps the single biggest key to upwind boatspeed. A competent mainsail trimmer can get you in the ballpark, but the true boatspeed virtuoso understands, feels, and can implement the changes on a moment-to-moment basis that make the difference. In a very real sense, they are driving the boat as much as the helmsperson. That’s why you often see them hunched over, (usually directly in line with the view of the helmsperson), as they ply their trade. They are looking at the same inputs to guide their sense of feel and dictate the appropriate reaction: angle of heel, jib telltales, boatspeed, waves, and wind angle.

continue reading » Getting a Handle on Mainsail Twist