??C30 Points of sail, trim and tuning?? - SailNet Community
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post #1 of 5 Old 10-16-2002 Thread Starter
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??C30 Points of sail, trim and tuning??

I just closed on a 1990 C30 wing keel, std. rig. I took the boat out yesterday for the first time with the 150 Genoa on the boat.
I had had it out several times prior with the main only. The wind was strong at about 20 knots. Although I was getting much more
heel, my speeds did not seem to increase much over using the main sail alone. I was topping out at about 4.2 knots. Yesterdays sail brought several questions and I was hoping to find a good resource to learn how to maximize performance of my boat.

Specifically I am interested in finding out about...
1) I was noticing that the Genoa often seemed to cause my main to luff, and although heeling a lot, speeds did not really
increase. Why?
2) What are the proper sail trims and tightness for points of sail?
3) What is the best point of sail for my boat?
4) When do I know if I should reef the Genoa and or Main?
5) Is my rigging tunned properly? How do I check it?
6) When sailing close to the wind, I was getting pretty subsatirical Heeling. How much heel can this boat tolerate prior to
becoming concerned about capsizing?
7)What is the most efficient heel angle?
8) How do I understand proportions of Main to Genoa reefing for most efficient combined operation?

Thanks a TON!
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post #2 of 5 Old 10-17-2002
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??C30 Points of sail, trim and tuning??

1) The 150% genoa is too much sail for 20 kts of wind. Because the boat was overpowered, it heeled excessively. When a sailboat heels excessively, the amount of drag on the underwater surfaces increases, and the boats slows down. Sailboats are designed to sail the most efficiently when they are relatively upright. If you reduce headsail area to 100 or 110%, and reef the mainsail, the boat will sail much more upright, and faster. The genoa gathers a large volume of air in the space between the headstay and the mast, and it funnels that air through the narrow slot between the genoa and the mainsail. When you see the mainsail luffing, that means that too great a volume of air is being forced through the slot, and it is lifting the luff of the mainsail. When you see the mainsail luffing and the boat is heeling excessively, that tells you that it is time to reduce sail area.

2) Generally, the closer you are sailing to windward, the tighter and flatter you trim your sails. As you fall off the wind, ease both the mainsail and the jib.

3) The fastest point of sail for most sailboats is a beam reach, but the best point of sail is the one that gets you to your destination in the shortest distance, the least time, and in the safest and most comfortable manner.

4) See the last sentence of #1, above, and see paragraph #8, below.

5) The website for the Catalina 30 National Association (catalina30.com) is the best source of information of this sort. On that site, Catalina owners share their knowledge and experiences on sailing, rigging, repairing and modifying the boat.

6) I donít believe that wind alone will capsize your boat. When the wind blows really hard, the boat will heel increasingly until she is lying on her side if you donít do anything to prevent it, but the ballast in the keel will prevent her from rolling over any further. I have seen some boats go over that far without even getting water in the cockpit. However, if a big wave rolls over her when she is in that situation, the wave can roll her over, mast-down. Nevertheless, the weight of the keel will act as a lever, and bring her back upright rather quickly.

7) The people at the Catalina 30 website can give you the best answer to this question.

8) In order for a sailboat to function efficiently, the forces exerted on the headsail have to be balanced against the forces exerted on the mainsail. The size and shape of the headsail has to be proportionate to the size and shape of the mainsail. As a general principle, the headsail generates the most forward drive, and the mainsail helps the boat point to windward. The particular disadvantage of the mainsail, however, is that it is more responsible for excessive heeling and for excessive tiller pressure than is the headsail. When the boat heels excessively and the genoa is backwinding the mainsail, and you feel excessive pressure on the rudder, it is time to reduce sail area.

When my boat is overpowered (excessive heeling or rudder pressure), and I am trying to decide whether to reef the mainsail or to reduce the size of the headsail, I completely ease the mainsheet while the wind is gusting. If the boat does not continue to heel excessively when sailing under jib alone, then I reef the mainsail. By reducing mainsail area, it will help the boat point to windward, it will reduce the rudder pressure, and the mainsail will not generate so much heeling moment. However, if the boat is still heeling excessively, or very nearly so, when I completely ease the mainsheet, then it is time to reduce the size of the headsail. When I reduce the size of the headsail, I usually tuck in a flattening reef in the mainsail. If that does not sufficiently relieve the rudder pressure or excessive heeling, then I tuck in the first full reef in the mainsail.
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post #3 of 5 Old 10-17-2002 Thread Starter
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??C30 Points of sail, trim and tuning??

Thank you so much for that insightful response!
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post #4 of 5 Old 10-19-2002
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??C30 Points of sail, trim and tuning??

A couple additional thoughts:

Many boats will not sail very well to windward under main alone.

If your sails are old, you will get more heel since older sails are stretched and are difficult to flatten, which will reduce heel. That brings up another point - as the wind increases tighten the outhaul on the main in order to make it flatter.
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post #5 of 5 Old 10-29-2002
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??C30 Points of sail, trim and tuning??

Ahoy, boardroom. It sounds like you equate heeling with speed. It is an illusion. A boat sails faster and better on her feet. Twenty knots of wind is a lot. Remember that the pressure on the sails increases as the square of the wind speed. That is, if the wind speed doubles, the pressure quadruples. At 20 knots you should have a jib up, not a genoa, and should be reefed. It helps to visualize what is happening and to understand the forces acting on your boat conceptually instead of academically. If you don''t mind doing some reading, I have several discussions on the board that will help you understand balance, heeling, sail trim etc. in a visual way. Look back and find the following discussions:
Under Learning To Sail, Aerodynamics of Sailing, Feb. 10, dhartdallas, Pt.1 and Pt 2.
Under Learning To Sail, Heeling Paranoia, Jul. 29, 4:24 PM, and Aug.28,4:21 AM.
Under Learning To Sail, Sail Trim For Beginners, Jul. 23, l:04 AM, and Dec. 12, 4:26PM.
Under General Discussion, Mast Rake For Cape Dory 30, Jul. 31, 12:59 AM.
You have two fundamental problems. You are over canvassed, and you are sheeting in too hard. These discussions will help you.
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