Association Forum - Quiet time

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

Catalina 25 Specific Forum

Quiet time

New Topic

Topic Locked

Printer Friendly

Author

Topic

Page: of 2

Stinkpotter
Master Marine Consultant

Members Avatar

Djibouti
9081 Posts

Response Posted - 01/21/2014 : 14:07:58

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by ftworthsailor
 I was amazed at how the older Catalina 22's were able to pull out in front with hardly any winds....<hr height="1" noshade id="quote"></blockquote id="quote">They'll do that--especially older ones that have been stripped for racing. Did you put your rail meat on the leeward side to induce some heel?

Edited by - on

ftworthsailor
Captain

Members Avatar

USA
279 Posts

Response Posted - 01/21/2014 : 14:25:48

Edited by - ftworthsailor on 01/21/2014 14:27:28

Steve Milby
Past Commodore

Members Avatar

USA
5902 Posts

Response Posted - 01/21/2014 : 14:38:12

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by ftworthsailor
 I watched as the two leaders (C22's) pulled away from us at the starting line. Then wasted about 4-5 minutes trying to get across the starting line with full, but limp sails. <hr height="1" noshade id="quote"></blockquote id="quote">Sailing in light air isn't about having a boat with light weight. On the contrary, I prefer carrying 2-3 extra crew in light air, to use as movable ballast. Light air sailing is about powering up the sails, keeping your sails driving when others' sails are hanging limp, and reducing drag. Some people know how to do one or two of those things, but very few can do all three well.

A good rule of thumb is that, if other boats have enough wind to sail, you should have enough as well. You have to figure out what they're doing that's different.

Edited by - Steve Milby on 01/21/2014 14:42:32

Steve Milby
Past Commodore

Members Avatar

USA
5902 Posts

Response Posted - 01/21/2014 : 16:22:00

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Dave5041
 Wow, it's really quiet around here this winter. Doesn't anyone have any questions about anchors, rodes or tow vehicles.

<hr height="1" noshade id="quote"></blockquote id="quote">Since we're suffering from not having anything to talk about, this would be a good time to talk about light air sailing.

The three elements of light air sailing are maximizing sail power, keeping the sails driving, and reducing drag. When the wind goes light, the first thing you should do is trim the sails for light air. That means ease the adjustable backstay until there is a slight catenary curve in the forestay. Then ease the jib halyard until the luff of the jib is relaxed, but still smooth. Then, ease the main halyard until the luff of the mainsail is completely relaxed, but still smooth. Next, ease the mainsail outhaul, until the mainsail has a deep draft. Move crew weight to leeward. That causes the boat to heel, so that gravity causes the sails to hang in that curved shape that drives the boat, intsead of hanging limp. When moving crew weight to leeward, you should also move them forward, in the vicinity of the mast stays. That causes the boat to sail bow-down. When the narrow bow is down, the fat stern is lifted partially out of the water. That reduces the boat's wetted surface, and by reducing the boat's wetted surface, you also reduce drag. Steer as close to the wind as you can, while keeping the sails full. Always steer with the lightest tiller pressure possible. Whenever you feel tiller pressure, it constitutes drag.

Continue with this trim until the boat's speed reaches about 2 3/4 or 3 kts. When it exceeds that speed, it's time to begin gradually adding tension to all the sail controls. When you are trimmed for light air, tell the crew to not move about the boat without pernmission. If the air is spilled out of the sails, the boat will lose momentum, and in light air, it takes a long time to regain it.

Edited by - Steve Milby on 01/21/2014 16:35:25

Stinkpotter
Master Marine Consultant

Members Avatar

Djibouti
9081 Posts

Response Posted - 01/21/2014 : 18:47:41

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Steve Milby
 ...Steer as close to the wind as you can, while keeping the sails full...<hr height="1" noshade id="quote"></blockquote id="quote">I agree with everything except maybe that. I've been led to believe that in a relatively heavy, modestly rigged boat in very light air ("cat's paws"), it's best to sail a little lower with the sheets eased a little, to get more drive from the sails and lift from the keel. Too high and your speed (such as it is) drops and leeway increases, possibly to the point that your true course is the same as when sailing lower, but you're slower. Trimmed a little looser, the driving force from the fuller sails is more forward and less to leeward, again for less leeway. The issue is best resolved by measuring VMG to windward with the GPS.

I'll add to Steve's light tiller that tacks and mark roundings should be somewhat gradual and wider so the rudder doesn't kill momentum through the turn. Then temporarily turn to a somewhat lower course than you want to end up on so you can get your speed back before steering and trimming to your new course. The lighter the air, the more important it is to go for "speed" (movement) to get the keel to work for you.

Very light-air sailing can be a great test of techniques, many of which are quite different from "normal" sailing.

Edited by - Stinkpotter on 01/21/2014 19:02:06

ftworthsailor
Captain

Members Avatar

USA
279 Posts

Response Posted - 01/21/2014 : 18:55:23

Great info, guys. Thanks!!

Edited by - on

Steve Milby
Past Commodore

Members Avatar

USA
5902 Posts

Response Posted - 01/21/2014 : 21:02:06

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Stinkpotter
 <blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Steve Milby
 ...Steer as close to the wind as you can, while keeping the sails full...<hr height="1" noshade id="quote"></blockquote id="quote">I agree with everything except maybe that. I've been led to believe that in a relatively heavy, modestly rigged boat in very light air ("cat's paws"), it's best to sail a little lower with the sheets eased a little, to get more drive from the sails and lift from the keel. Too high and your speed (such as it is) drops and leeway increases, possibly to the point that your true course is the same as when sailing lower, but you're slower. Trimmed a little looser, the driving force from the fuller sails is more forward and less to leeward, again for less leeway. The issue is best resolved by measuring VMG to windward with the GPS.<hr height="1" noshade id="quote"></blockquote id="quote">
I think we're saying the same thing, basically. Whether sailing in strong wind or light air, the objective should always be to maximize boat speed. You should steer whatever course is necessary to maximize boat speed. That course will be constantly changing, because you will be sailing through lifts and headers, and puffs and lulls. The reason why it is crucial to maximize boat speed is because as boat speed increases, the boat's ability to sail close to the wind also increases. When sailing to windward, whether in light or heavy air, if you sail as close to the wind as you can while maximizing boat speed, you will also maximize your VMG.

Edited by - on

cshaw
Captain

Members Avatar

USA
460 Posts

Response Posted - 01/23/2014 : 07:57:11

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Steve Milby
... Next, ease the mainsail outhaul, until the mainsail has a deep draft.
<hr height="1" noshade id="quote"></blockquote id="quote">
Good advice Steve, but I would use some caution with making the sails "too" full for going upwind in light air.

We generally do better in light air when close hauled by keeping the sails flat. That means the outhaul still has tension on it, and the jib leads are not moved "too" far forward. The best lightair headsail I have ever used was a mylar 155 that I built with a camber ratio of 17:1 on the advice of John Kolius (who sailed on Galveston Bay, and no I never beat him but I sure tried!).

The other thing to concentrate on is the ability to quickly and SMOOTHLY shift gears when going up wind. As the wind drops off, get the sails full and fall off a bit to keep that all important momentum up. Then as it builds back from the lull, flatten and trim in SMOOTHLY.

Remember, the wind is usually strong up off the water, so those are the most important telltales to watch for seeing the wind changes....

Reaching I agree totally with making them full (easing the outhaul and the jib leads forward)

Cheers!!

Chuck

Edited by - on

Steve Milby
Past Commodore

Members Avatar

USA
5902 Posts

Response Posted - 01/23/2014 : 09:56:46

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by cshaw
 <blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Steve Milby
... Next, ease the mainsail outhaul, until the mainsail has a deep draft.
<hr height="1" noshade id="quote"></blockquote id="quote">
Good advice Steve, but I would use some caution with making the sails "too" full for going upwind in light air.

We generally do better in light air when close hauled by keeping the sails flat. That means the outhaul still has tension on it, and the jib leads are not moved "too" far forward.<hr height="1" noshade id="quote"></blockquote id="quote"> There seem to be two schools of thought on that question, Chuck, but I think the difference is more in differing perceptions than in substance.

The adherents to the "flat sail" school of sail trim maintain that, even in very light air, the wind can't stay adhered to the surface of the sail if the draft of the sail is too deep. If the flow separates from the surface of the sail, especially the convex surface, before it flows all the way across it, then you'll lose power. That is a fundamental principle of aerodynamics, and I completely agree with it, even though, when these discussions pop up, I am an adherent to the "full sail" school of thought.

The adherents to the "full sail" school of sail trim maintain that, when the ambient wind is so slight, the first thing you have to do is to just get the boat moving. In order to do so, you need to draw upon as much power as you possibly can. The adherents to this school believe, as I do, that somehow, you have to find the peak of the sails' power curve.

The reason why light air sailing is so difficult is because you might only have 2 kts of wind to drive a 4,000 lb, or even a 20,000 lb boat. When you have so little driving force to work with, you can't waste any of it.

As a general principle, you power up a sail by increasing it's draft, and depower it by flattening it. So, my approach to sail trim is generally to start with them a bit more full than I think is necessary, and then, after the start, tweak the sail trim. By doing it that way, I know I'm starting from the outside limit of the sail's power curve and, in order to find the peak of the power curve, all I need to do is to progressively trim it flatter until the knotmeter tells me we're there. Doing it that way serves two purposes. First, it gives the boat maximum power to accelerate during pre-start maneuvering, and after the start. Secondly, in order to find maximum speed and pointing after the start, all I have to do is to progressively trim in the sail controls while watching the knotmeter. If I flatten the sails too much, the knotmeter will tell me so. If boat speed continues to increase each time I trim the sails a little flatter, then that tells me that the sails aren't at optimum trim yet.

It might seem like it would take alot of time to find the peak of the power curve by this trial and error method, but in reality, with practice, you learn about where to find it.

When you discuss it in detail with the adherents to both schools of thought, you'll usually find that they really agree much more than not. Contrary to popular belief, sail trim is a science, not an art, so, if you and I are both getting good light air results, we're probably using very similar techniques.

Edited by - on

Stinkpotter
Master Marine Consultant

Members Avatar

Djibouti
9081 Posts

Response Posted - 01/23/2014 : 11:52:36

Also, there's light and there's LIGHT... on most boats I'm familiar with, 5 kts of air calls for one kind of sailing, and 2 kts requires another. 2 kts is "anything we can do to get moving ASAP" sailing, while 5 lets us do things that are closer to normal trimming and steering. In my admittedly limited formal racing experience, "anything" generally means fuller and lower. (...and moving everyone to leeward.) At 5 kts true and maybe 7 apparent, we start flattening and pointing (carefully). And as suggested, fluctuations between the two lead to variations in tactics.

Edited by - on

Page: of 2

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.