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stampeder
Master Marine Consultant

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1608 Posts

Initially Posted - 07/17/2006 : 11:02:27

We were at a race clinic this weekend. The coach was telling us that optimum heel while close hauled would be between 15-17 degrees. Is he right?

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Champipple
Master Marine Consultant

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USA
6855 Posts

Response Posted - 07/17/2006 : 11:40:13

I'd say more like 12. unless its blowing like stink, then flatter is better

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Frank Hopper
Past Commodore

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Pitcairn Island
6776 Posts

Response Posted - 07/17/2006 : 13:17:17

It really is hull specific, some hulls pick up waterline with heel, some gain or loose wetted surface. I know I used to work really hard to keep my dingy flat but in a Catalina 25 it just feels right with some heel. The physics of the forces on the sails begs for flat regardless of the boat though.

Edited by - on

JimB517
Past Commodore

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USA
3285 Posts

Response Posted - 07/17/2006 : 14:49:43

I think the boat works best at 15 degrees of heel, but 20 feels really good too. The theory is the waterline is longer when heeled thus the boat is faster.

In light air get weight to the lee side to make it heel over to 15.

I love sailing at 30 to 40 degrees of heel, but you are losing speed. The C25 won't heel past 45 without rounding up. Start flattening sails around 15 - 20 degrees, reefing around 30.

Edited by - on

Bruce Baker
Captain

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USA
402 Posts

Response Posted - 07/19/2006 : 15:40:44

I used to sail with a real keen racer-type who said that every boat should heel at exactly 17 degrees. I'm not sure that I agree that EVERY BOAT boat should heel the same, but I think it's a pretty good figure for the C-25. My boat really takes off and points like a demon with 17 degrees of heel.

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stampeder
Master Marine Consultant

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1608 Posts

Response Posted - 07/19/2006 : 15:58:44

15-20 degree range does feel good. Especially now, thanx to racing and coaching, we've figured out how to trim our sails without dragging the rudder like a brake.
Kinda funny tho', because the admiral and I were getting comfortable with sailing with the rail in the water. I'm suprised now that I didn't snap that rudder off...I was developing Popeye arms fighting off rounding-up.

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djn
Master Marine Consultant

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USA
1561 Posts

Response Posted - 07/19/2006 : 18:57:49

Hi stampeder, I was developing the arm as well. I sailed today for a couple hours but the winds were 5 to 10 so it was more of a meander than a sail. I was hoping for greater winds so I could play around with reefing and see if I could keep the lean down to 20. Maybe tomorrow. Cheers.

Edited by - on

tmhansen
Captain

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USA
397 Posts

Response Posted - 07/20/2006 : 01:06:37

Mike you raise a point I have been meaning to ask here. Sounds like you were experiencing the same as we.

We did a local yacht club race at Port San Luis. The 2.3 mile course started near the Avila pier where the winds were light and took us out to the breakwater where the prevailing winds were strong and then back to the pier. Everyone raced with full sails. We crossed into the ocean wind just before the weather mark and did one leg in it before gybing back into the light stuff. During the downwind deep reach the boat turned up toward the wind, not a full round up but similar. I could not get it to turn down again for a while. We tried easing the jib and hauling it in. I did not change the main as it was alread out all the way. Once I did manage to get turned down again on course we were fine until a lapse in my attention and a wave turned us up again. I suspect we just had too much sail up and I should have taken a few turns on the jib furler. This just seemed counter intuitive as reducing foresail would it seem make it more likely to round up. I did not want to reef the main since I would need full sails again shortly. What have you learned? What should I have done?

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djn
Master Marine Consultant

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USA
1561 Posts

Response Posted - 07/20/2006 : 05:54:29

Hi Todd, if you read through the thread "I wish I'd gone for the new style rudder". this is covered fairly well. I can't wait to get out in the same conditions to try different approachs to cure the problem. Cheers.

Edited by - on

britinusa
Web Editor

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USA
5404 Posts

Response Posted - 07/20/2006 : 06:43:51

Flat = Admirals Smiles and Camera pics
5daoh = Admiral Sitting down Camera stowed.
10doh = Feet braced, tune to weather channel.
12doh = Feet braced, Concerned looks.
14doh = Feet braced, grabbing hand holds.
15doh = Feet braced, Requests to ease up, Looking around for lifejacket.
16doh = Wearing lifejacket, pleading to ease up and furling.
17doh = Handheld vhf ready in hand, Pleas for reefing and furling
18doh = Ready to inflate the dinghy, Checking GPS for lat & lon
19doh = Threatening to abandon ship, safety bag in hand, dinghy inflated, tuned vhf to distress channel.
20doh = Lawyers following in power boats with divorce proceedings.
20+doh= Anyone want to buy a boat?

paul

Edited by - on

Arlyn Stewart
Master Marine Consultant

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USA
2980 Posts

Response Posted - 07/20/2006 : 08:20:58

When a sailboat heels, its footprint changes from symmetrical with equal chines to asymmetrical with the leeward chine and the windward boat bottom.

In light air, gaining water line length wouldn't have any effect but reducing wetted surface and drag does. Heeling (especially when combined with moving weight forward) reduces the amount of immersed rudder and reduces the draggy wedge footprint (fine entry spreading wide aft).

In a breese, the forward power of the sailplan will ratchet the bow down and crew weight is shifted aft to counter.

Excess heel causes the asymmetrical footprint to do some rather interesting things. Remember from science class that an asymmetrical foil offers lift towards the longer side. This means that when heeled, the leeward chine forms one side of the foil and the boat bottom (rocker) forms the other.

With a wide hull form with a near 3:1 length to width ratio, the chine foil is much more exagerated than is true for a narrower longer boat. On these boats then the asymmetrical footprint is pronounced and will display greater lift potentials.

Unfortunately, the lift is to leeward further exasperating windward performance... hence on one of these hulls, it is imperative to sail them to windward without excessive heel.

The lift to leeward is not the only problem however, its center also comes into play. If the center is not close to boat balance, it will induce a yaw force (usually severe weather helm). Remember also from science class, hydro forces are exponentially greater than air medium. A foil that would generate moderate forces in air can generate extreme forces in water. And, of course... all yaw forces have to be countered by lifting forces of either the rudder or sailplan and both equate to increased drag.

Racing sailboat designs seek a hull form that doesn't offer an asymmetrical footprint with leeward lift. Those having a bottom rocker sufficient to provide a corresponding water line length to the chine avoid the problem of being hard mouthed (suffering adverse weather helm when heeling). In fact, mono hull forms can be designed with lifting forces to weather.

I've exchanged mail with a one meter modeler in the UK who explained that to be compeditive, one must now have a lifting form to weather. There are two significant challenges in such a design. First in getting the lift to weather and then in the doing, having its center properly set and favoring forward of the boat balance center rather than aft of it as typical to our C25 or 250. The reason obviously is an aft of center leeward lift will create weather helm but an aft of center windward would create dreaded leehelm.

Leehelm would counter the whole effort of gaining windward lift because it would destroy the positive windward angle of attack the rudder enjoys with a bit of weather helm.

Some interesting stuff....

Edited by - Arlyn Stewart on 07/20/2006 08:33:50

existentialsailor
Master Marine Consultant

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USA
1180 Posts

Response Posted - 07/20/2006 : 08:22:03

Doesn't the direction you are sailing in relation to the wind affect what is better heel?

I know when I'm on a reach if I bring Swimmer down to 10 degree heel I'll pick up half a knot. If I'm sailing downwind, as little heel as possible seems to be best.

Admittedly, my knowledge level is still in the novice level of ability, am I missing a basic dynamic?

Edited by - on

Steve Milby
Past Commodore

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USA
5906 Posts

Response Posted - 07/20/2006 : 09:32:04

There's no reason why your boat should have excessive weather helm or lee helm. By adjusting the rake of the mast, you can adjust the forces on the sail plan so that they are properly balanced with respect to the forces on the keel and rudder. If those forces are adjusted correctly and you still have excessive weather helm, then the helm pressure can be reduced by either good sail trim (i.e., adjusting the sail shape correctly for the windspeed and conditions), or by reducing sail area.

Recently one of our contributors (I think it was Ben) said he reduced sail area on his boat during a race with a lot of wind, and he commented about how light the helm pressure was, even though the wind was blowing hard. He got all the forces on the sailplan equally balanced against the forces on the keel and rudder, and the result was light tiller pressure.

If your arms are starting to get muscular from fighting the tiller, try to reduce the pressure first by trimming the sails, and if that doesn't work, try reducing sail area by the minimum amount necessary to reduce the tiller pressure.

Edited by - on

Lightnup
Master Marine Consultant

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USA
1016 Posts

Response Posted - 07/20/2006 : 10:24:18

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by britinusa
 Flat = Admirals Smiles and Camera pics
5daoh = Admiral Sitting down Camera stowed.
10doh = Feet braced, tune to weather channel.
12doh = Feet braced, Concerned looks.
14doh = Feet braced, grabbing hand holds.
15doh = Feet braced, Requests to ease up, Looking around for lifejacket.
16doh = Wearing lifejacket, pleading to ease up and furling.
17doh = Handheld vhf ready in hand, Pleas for reefing and furling
18doh = Ready to inflate the dinghy, Checking GPS for lat & lon
19doh = Threatening to abandon ship, safety bag in hand, dinghy inflated, tuned vhf to distress channel.
20doh = Lawyers following in power boats with divorce proceedings.
20+doh= Anyone want to buy a boat?

paul

<hr height="1" noshade id="quote"></blockquote id="quote">
Paul - I see you've sailed with my wife.

Steve

Edited by - on

Champipple
Master Marine Consultant

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USA
6855 Posts

Response Posted - 07/20/2006 : 11:13:38

I have a wife who is an avid racer mine would look like this

0-15degrees - This fat pig is slow
15-16 - wow your fat a$$ slow boat takes a lot of breeze to get this heel You guys need to get rid of the head and the microwave and the table.
16-20 Do you realize that the mark is over there, get some of your fat crew up here on the rail so you can point higher you moron
20 + Wow - with 18 knots of breeze and this phrf rating we might actually beat someone

Edited by - on

stampeder
Master Marine Consultant

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1608 Posts

Response Posted - 07/20/2006 : 11:38:13

Todd - I'm not qualified to give advice.

But I will share my experience and what I learned so far; the helm should be light. Helm Pressure means adjust your sails. My understanding so far, is if you have let out your main all the way and you are still over-powered, you have to reef. (you should already have reefed)
We sail during the summer on an extremely windy lake where wind direction changes often. I have my sails rigged so that I can reef and unreef quickly.

Racing clinic also taught us to spend more time prior to the start of the race setting up our rig for existing race conditions. For us this generally means getting the main as flat as possible.
I'm not reluctant to put a reef or two in because my experience is that I can sail just as fast or faster.
Frank Hopper made a point that stuck with me about a year ago - he said that if he reefed he still had to have proper sail shape - that continues to make emminent sense to me.

Another major factor on our boat has been jib car placement. We change car position frequently during a race. When we sail close hauled, we bring them back so we can point higher, when we're on a run we move them forward, and on reaches we tend to move them to the middle.
Racing has been an excellent teacher.

Edited by - on

Champipple
Master Marine Consultant

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USA
6855 Posts

Response Posted - 07/20/2006 : 13:13:25

I’ve been racing for quite some time and we never moved the jib cars on the down wind leg. I sat here and mentally beat myself up….why didn’t/don't I do this. I adjust everything else, how could this have possibly slipped my mind? While thinking about all these things, my buddy shot me an email expressing his concern that he didn’t think anybody listened to him last night when he said the spinnaker might have gotten a small pinhole while dousing after the second downwind leg……

DOH

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wmeinert@kconline.com
Past Commodore

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USA
353 Posts

Response Posted - 07/20/2006 : 19:10:03

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Frank Hopper
Past Commodore

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Pitcairn Island
6776 Posts

Response Posted - 07/20/2006 : 20:25:11

riveting Bill!

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atgep
Master Marine Consultant

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1009 Posts

Response Posted - 07/21/2006 : 08:09:17

What about the wing keel? Mine seems to be in the groove at 20-30 deg.

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Dave Bristle
Master Marine Consultant

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Djibouti
10005 Posts

Response Posted - 07/21/2006 : 09:34:49

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by atgep
 What about the wing keel? Mine seems to be in the groove at 20-30 deg.
<hr height="1" noshade id="quote"></blockquote id="quote">
You might be going smartly through the water, but with that shallow wing, I suspect at that angle you're getting a lot of leeway. Point the boat at a landmark and then hold your compass bearing precisely and see how much you're drifting to leeward. Then trim for 15-20 deg. and try the same test.

Edited by - Dave Bristle on 07/21/2006 09:36:54

Alan Clark
Captain

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406 Posts

Response Posted - 07/24/2006 : 07:28:17

Duane, Has my wife been sailing with you? The only thing missing was are you sure we need to reef? :)

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HeelinPatrick
Navigator

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USA
102 Posts

Response Posted - 06/18/2009 : 08:39:38

Still diggin' thru the old posts...

So, what are the optimum heel angles for the various points of sail, with racing in mind??

At one point I read something about 25 to 28 deg upwind is the quickest, but this thread is more of 15 to 20. In light air, does it make sense to use the rail meat to induce heel, or is flat good? On a reach, want flat, or some heel? What happens if heel more than optimum going windward, is there a trade off, like less pointing, but more speed? Or if less heel, better pointing, and less speed?

I know there is helm induced with heel, but assuming rig/sails could be adjusted to remove helm, what are the best heels?

Considering my user name, this would be good for me to know!

Edited by - on

Steve Milby
Past Commodore

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USA
5906 Posts

Response Posted - 06/18/2009 : 09:16:02

I think between 15-20 deg. heel is about right for sailing to windward, but racers often sail with a much greater angle of heel, even though they know it's slow, because the windspeed has increased since the start of the race, and they know the boat is overpowered and that it would sail faster with less sail area, but they don't feel they can take the time needed to change the sails or tuck in a reef while the race is ongoing. As long as nobody else is reducing sail area, they won't reduce it.

When on a reach, I generally don't concern myself with the angle of heel, because it sort of takes care of itself. When you're reaching, the forces on the sails are directed more in a forward direction, so the boat is less likely to heel excessively. When you're beating to windward, the forces on the sails are predominantly sideways, making the angle of heel more of an issue.

When sailing in light air, the crew weight should be moved to leeward and forward, so that the boat is heeled to leeward, and bow down. As others have explained, it reduces the amount of wetted surface. When heeled a little, the shape of the hull is more efficient, and when the boat is sailed bow-down, it raises the boat's fat stern out of the water, reducing wetted surface. Wetted surface constitutes drag.

Edited by - on

aeckhart
Master Marine Consultant

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USA
1709 Posts

Response Posted - 06/18/2009 : 10:59:19

I have to agree with atgep. I've been sailing my wing keel for 20 years and have found that heel angles of 20 degrees or more favor upwind sailing especially in winds above 12 knots. Because of it's shallow draft the wing keel does not adequately resist leeway when sailing with even a moderate heel. When vertical, the wings seem to create more bight and therefore more resistance to leeway. I'm not an expert in hull dynamics but that's what my expeience tells me.

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bigelowp
Master Marine Consultant

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USA
1788 Posts

Response Posted - 06/18/2009 : 17:57:03

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