Optimal Heel Angle

[bob perry]

What's this "passive -agressive" BS? I dont even know what that means.

Let's just discuss this stuff like a bunch of enthusiasts who are in the never ending process of making ourselves smarter. Why just today that knucklehead Slowshoes taught me a lesson I have never found in a book. He's one smart knucklehead.

Some cats may want a small heel angle to get their windward hull out of the water to reduce wetted surface.

[Sailmonkey]

Originally Posted by bob perry

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Some cats may want a small heel angle to get their windward hull out of the water to reduce wetted surface.

True, but much beyond and you have diminishing returns. My Inter17 has canted hulls, 4.5deg i think. If I heel the boat more than about 5 or 6 degrees while on a beat i'm having a hell of a time walking the dog but not going as quickly as I'd like to be towards the weather mark. So this whole thread really applies to mono and multi.

[lawdawg]

This has been a really educational discussion with some great information and it is really great to get Bob's opinions on all this. Your Norseman 447, Passport 40 and Tayana 37 were all a part of my current boat search........the valiant 40 was too expensive
Definitely looking forward to following this thread

[bob perry]

My opinions are just that. I've worked hard for many years to learn this craft and I think it's good for me to pass along what I have learned.

[Blue Stocking]

My 1965 built, skinny hull, deep draft Rhodes Reliant sails best at the angle just as the beer slides to l'ward on the cockpit table. The beer has to be 50% gone, with a thin film of condensate formed.
S&S, I could crew for you. Our boats have simple trim criteria, as outlined above.
And Bob is welcome to X 3

[sabray]

maybe this is some myth. I thought those older gorgeous boats with massive overhangs and no waterline did that because they knew they were going to heal and when they did the waterline jumped in length increasing the max hull speed. just for example if you tipped Hereshoffs new york 30 on edge a little the water line might double. Im sure this is a wives tale.
my new disclaimer
In no way do I mean to demean the tale of a wife by inferring the remark which is a gender sensitive suggestion associated with bad information. Any advice which may considered as a financial suggestion should be disregarded. Further more if at any point you feel inclined to apply a suggestion made within this post you should do so understanding it is at your own risk . All information is of a confidential nature and should be considered with a grain of salt.

[FraidNot]

Crikey - who hijacked my thread ?
It seems that no one has emperical or test data that relates polar charts to heel for the Oceanis range. Suspected as much. Thanks for those that did contribute - appreciated.

For the very interesting and theoretical mass of detail there - that is probably a good topic in itself but not quite what I was chasing. Thanks again.

[Bash]

Originally Posted by bob perry

Bash:
I think we are limirted here to boats with pops in apertures where in some cases the aperture can be 20% or more of the total rudder span. So add turbulence off the aft end of the hull cutout, the crudely radiused front end of the rudder portion of the cut out and the area of the three blades and you have seriously reduced the effectiveness of the rudder.

I do not think this would apply to most modern designs with props out in the open.

good point. that would certainly effect the helm.

the message here has to be: don't tow a bucket in front of your rudder.

[seabee]

NOTQUITELOST----- sorry to see that a they do not allow a sense of humor in your area, I guess you had the option to not read it --SEABEE

[sailorboy1]

Originally Posted by Bash

the message here has to be: don't tow a bucket in front of your rudder.

finally something my pee brain can get without any problem

[bob perry]

Don: I'm with you. Many years ago I was designing an all out quarter tonner for a Seattle client.

I was musing over changes in the keel and ballast weight and I put my question to a good sailing buddy who had a mind for math. I asked him, "Do you think another 150 lbs. would make that much difference?" His answer was, "Imagine Dick Jones ( a 300 lb. friend of ours) sitting on the rail."

It's good to reduce these elements to components we can understand.

[GeoPowers]

Originally Posted by FraidNot

GeoPowers - thanks that would be handy.
I sail with reference to the polar charts and these are very useful for seeing how close to original test data you can get. Handy indication of quality of trim.
You will see the race boats at 15 to 20 quite often - working hard against each other and all at that heel. I suspect a cruise/racer like Oceanis is indeed best at 15 or less but really seeking any emperical evidence, or long term user experience by someone who has worked on this idea.
Mark - you out there ?

Hey Fraidnot, ran into my dock neighbor the other day. He said (in a nutshell) 1) When cruising 12-15 degrees is the heel angle recommended. 2) optimal heel is of course actually 0, but impossible (duh). 3) When racing, he will generally take the more power route and just deal with the leeway (reefing based largely on the pucker-factor). 4) He, like I, have a furling main. He said when he shifted to vertical battens he noticed a more pronounced heel angle, but with the usual benefits of battened systems. 5) When sailing to windward, he used the main to "twist" into the wind so he could point a few degrees higher. At this point he went into racing blah blah blah stuff , but from what I gathered he'd heel more, but point better with a sheeted in main. This I believe was based on the much larger sail area of the head sail vs. main for the furling main system.

Hope this helps -

Frank.

[Factor]

the flatter the better, and its the same in my multi world, why do you think big fast boats have canting keels, cause they like spending money? I would think that Mr Perry has made it fairly clear.

[GeoPowers]

Originally Posted by Factor

the flatter the better, and its the same in my multi world, why do you think big fast boats have canting keels, cause they like spending money? I would think that Mr Perry has made it fairly clear.

So we should all be DIW and keep our sails flogging in the wind so we can stay at zero then, huh?

I don't think the OP cares about the theoretical optimum heel angle for all boats in a perfect closed environment. He was asking for real world experiences on a specific model boat.

[NCountry]

I had a lot of opinions on this subject before I crossed the Gulf from Key West to Galveston last month. Two Northers later, big waves, big wind and a compass that rocked so wildly it did everything but spin upside down. I now have a much more enlightened opinion.
Big seas and big winds require that you sail flatter. Amazingly our VMG during the trip went up when we were flatter and our ETE dropped. It occured to me during a night watch as I noticed these things that really a passage isn't any different than racing. The whole point in BOTH cases is to get there as fast as possible. It's just that with a passage you have the added benefit of seeing the results of your sail trim over a longer period of time.
I used to push my boat as hard as I could to heel, to a point. The GPS told me I was going faster. Because of the limited amount of time involved with that approach in terms of the length of the sail it seemed to make sense. However, with a good 6 day passage you really start looking at those VMG and ETE numbers AND you notice that you can have a slower GPS COG speed but improve your ETE and your VMG. It's a perspective you don't get for very long when racing around the cans.
This doesn't even begin to talk from the perspective of crew comfort over a longer period of time or address issues like cooking, eating and sleeping. All of which in the end actually contribute to or detract from the proper operation of the boat which includes sail trim.
Sorry this comes such a long time from the date of the original post. It's taken me a number of years to learn this lesson...... I'm a little slow like that sometimes.