Close hauled in an Ericson

[e38 owner]

Boat speed makes every tactician look good

 

[supersailor]

Used to do very well tacking immediately on the shifts in lighter air. Had a worn out crew, though.

 

[Jenkins]

Great point.

If one were to plot boat-speed against wind angle, you get what is called a "polar diagram"

Sailing at an angle like "B" feels fast. Sailing at a wind-angle like "A" feels slower (in fact, *is* slower, according to the knotmeter), but gets you to a weather mark faster. Because it is the best "VMG" - Velocity Made Good toward the mark.


View attachment 25055

Is it possible you had your A's and B's mixed up?

A polar diagram is boat speed plotted versus course off the wind. So the distance from the origin at any given angle is the boat speed at that angle. Another way to think of it is if you plotted the velocity vector with its tail at the origin, its tip would fall on the polar curve

At point B the boat is sailing at an angle of 40 degrees with respect to the true wind direction at speed of about 6.4 knots.
At point A, it is sailing at an angle of 50 degrees with respect to the true wind direction at speed of a little better than 7 knots.

However, at point B the VMG is greatest because the component of the velocity into the wind direction is greater than at point A.

A bit technical - VMG = (boat speed)*cos(true wind angle)

Point A VMG=7cos(50)=4.5 knots
Point B VMG=6.4cos(40) = 4.9 knots

Practical advice - best VMG occurs at the angle where curve on the polar diagram is horizontal.

Peter

 

[bgary]

Is it possible you had your A's and B's mixed up?

Good catch! I vaguely remember noticing that when I uploaded the image, but (obviously) forgot to fix it. It is now fixed.... thanks!

Practical advice - best VMG occurs at the angle where curve on the polar diagram is horizontal.

Spot on (true both upwind and down)

Bruce

 

[Loren Beach]

Sometimes a thread has so much great information in it that it just deserves a 'bump'.
"Ready About!"

 

[TKBLACK]

"in general", your sails will tell you everything you need to know.

The things to watch for are
-- the gap between the bottom spreader and the jib. 4-6" off the tip of the spreader is probably as much as you want.
-- the telltales on the inside of the genoa luff. If the top ones lift first, the genoa car is too far aft. If the bottom ones break first, the car is too far forward. adjust the car forward or aft until they all lift at about the same time.
-- the leech of the sail. you want it to be smooth, not "hooked"
-- the top batten of the main should be parallel to the boom in light to moderate breeze. If the wind is up, let the main twist off a little too.
-- the telltales on the leech of the main should be streaming, with the top telltale maybe "hiding" behind the sail from time to time.
-- keep any eye on the "slot" - the curve of the back of the jib should be the same shape (top to bottom) as the curve of the back of the main. (choking off the slot - having the jib pulled in too tight - is a sure way to slow down)

There are variations to consider - in more wind, you may want to move the genoa car farther aft than normal to let the top of the jib "twist off" and open up the slot between the jib and the main. You can generally tell it is time to do this when the front third of the main is backwinded.

in breeze, pay attention to the angle of heel. heeling a lot is slow. If you're heeling too much, "feather" (steer a touch closer to the wind), especially in puffs

It's also important to let the boat get up to speed coming out of a tack. Sail the boat a little "fat" (a little below optimal course, just a few degrees) until it has accelerated up to speed. If you grind in the jib right away, it'll take much longer to accelerate.

Beyond that... it's feel. and time spent developing it in a variety of conditions. You'll come to know when the boat feels like it is in the groove...

$.02

Thank Gary,
I want to print your words for handy reference. Your knowledge is valuable beyond the 2 cents.

 

[Christian Williams]

Want to go back to age 12, with a championship coach? (8 minute video)

I learned a lot from what he puts these kids through.

 

[kapnkd]

Keep the boat moving, especially in slop or when approaching and rounding marks among other boats.

The mainsail trimmer should concentrate 100 percent on the top batten. That indicates degree of twist, which is power (to push through waves) vs. speed (flat water, perfect conditions).

The person on the jib winch watches the telltales.

They both listen to the helmsman, who dictates corrections.

If he sees a wake coming, or a lull in wind, he announces a course correction and the new settings. To windward, this is a constant ongoing coordination, all subtle.

Keep the boat going. Pinching is fatal. When in doubt let it out.

Perhaps the best basic thing,”Keep the boat MOVING”! …Let the boat tell you with her boat speed. Our old ‘73 32 puts her shoulder down a bit and finds her grove. Just let the boat also talk to you…so to speak!

It becomes a delicate mutual intuitive feeling and communication between you and your boat

 

[G Kiba]

If all of the previous variables were not enough!
Please consider that different boats seem to like a specific sail trim and that sail controls and settings vary to some degree of effectiveness from boat to boat under different sail combination. Get to know YOUR boat and how to sail it to its best performance! Also, don't forget the wisdom of local knowledge. Watch the people who do good. Follow them when possible but don't forget their boat may also have different sailing characteristics. Lastly. Consider the current, your course, and the resulting keel exposure. Sailing a course with the current pushing against a larger keel area may slow and push you in the wrong direction. Reducing the keel exposure on another tack may be a smarter move. Welcome to the fun of racing! Winning is overrated. Meeting the challenge, over-coming the difficulties along with your competitors, and doing your best is a lot more fun! For me, the participation award is worth the entry and effort.

 

[frick]

My montra to keep a boat moving fast in the race is ways fight for clean air.
The helms job is sail the genny. If we want to point hight move the jib sheet cars aft. When going down wind move those cars forward. Also in Down wind without a spinnaker never said dead down wind, but said off just enough to keep your genny pulling.