Flat or heeled? If so how much?

zz4gta · #1 (**permalink**) 03-12-2008

I plan to do some club racing on the chesapeake this season as well as a longer distance race. I've heard people say a sailboat goes fastest when its upright. Others I have talked to say nothing more than 10* heel. Others (who I agree with) say it depends on the hull shape.

I'd like to know, for my boat (Merit 25), what would be the optimal heeling angle for max speed. I know there are a lot of variables but I'm curious to see what everyone's opinion would be. B/c I have no idea.

Thanks.

Giulietta · #2 (**permalink**) 03-12-2008

The straighter the better.

Very very basically, once you start heeling, the angle between mast and sail and the wind incrases and the wind starts spilling "upwards" in an easier manner.

The hull also plays an important role in making the heel cause loss of efficiency as the drag inreases, as wet surface is added, the unbalance between one side and the other also cause drag..etc.etc.etc.

Really, the straighter the better, that's why you see canting keels and all kinds of trim...to help reduce heel.

Race boats, try to minimize that loss by having "rounder" hull shapes.

TrueBlue · #3 (**permalink**) 03-12-2008

Quote:

Originally Posted by Giulietta

The straighter the better.

Although Giu, don't sailboat hulls with long overhangs experience a longer waterline when heeled beyond a certain point? That equates to greater hull speed.

Giulietta · #4 (**permalink**) 03-12-2008

Actually that kinda compensates for the loss of speed caused by the heeling, so the boat moves at near same speed..it's almost like a cheat...but in ver well dsign hulls may very well be true.

TrueBlue · #5 (**permalink**) 03-12-2008

Quote:

Originally Posted by Giulietta

Actually that kinda compensates for the loss of speed caused by the heeling, so the boat moves at near same speed..it's almost like a cheat...but in ver well dsign hulls may very well be true.

As demonstrated by your well-designed boat with a plumb bow and reverse transom. Heeling actually reduces waterline length.

Giulietta · #6 (**permalink**) 03-12-2008

Read this article...I find it very intersting

PBzeer · #7 (**permalink**) 03-12-2008

I think a lot of people "feel" like they are going faster when heeled. Obviously, with any amount of wind at all, there will be some heeling, but I agree with Alex that the flatter the better. At least that has been my experience with the boats I have had.

SailorMitch · #8 (**permalink**) 03-12-2008

ZZ4 -- I suggest posting this question on Sailing Anarchy because there are people on there who own/race Merit 25's. You'll get a load of info from them on this boat. Yes, Sailing Anarchy can be a bit rough and tumble, but ignore that if it comes up and focus on thosw with experience on the boat.

While it's generally true as Giu says, the flatter the better, designers also have optimum heel angles in mind when they design a hull a certain way. That's why I suggest going to Sailing Anarchy because it's Sailing Anarchy forum is filled with racers.

chucklesR · #9 (**permalink**) 03-12-2008

Even Giu admits heeling is not good, but can a catamaran sailor get a little respect? Heck no, not on sail net.

ZZ4gta, my buddy sails a Merit 25 - keep the heel to the minimum for maximum speed. Your overhang will add an insignificant amount of LWL to your theoretical maximum displacement speed (do the math at varying lengths and see for yourself). More importantly - heel causes more helm, more helm causes more drag. Heel also causes asymmetrical boat shapes under water which also adds to helm and wave action.
Balanced and upright is better for speed around the bouys.

Play the main sheet, jib trim and vestigial traveler on the merit for all they are worth. Go out on non-race days with your hand held GPS and measure changes in speed caused by changes in helm/trim etc.. Debrief yourself on what works and what doesn't. Note differences in speed on a given heading off the wind, tack and repeat - see if one tack is faster than the other and if so adjust your standing rigging.
If you get bored on a friday drag yourself up here and we'll do some sailing.

nolatom · #10 (**permalink**) 03-12-2008

I vote with heeling 10 degrees (and no more than 20 if it's really windy), only because I don't know any better. Use a gps to see which is faster, 10 or zero. I'm thinking 10 because there's less wetted surface (even though your remaining wetted surface is deeper), but my racing experience is decades old, so maybe some of the newer designs prefer no heel.