Reefed Sail related to loss of pointing up wind?

I think the issue is the sail is reefed period. The sail was most likely designed to be most effective when the sail is completely out. Any act of reducing sail reduces the airfoil shape and draft which reduces/hinders perfomance. Additionally the airflow around the mast is now interrupted because the sail is no longer centered behind the mast. In the end I think up wind perfomance is going to be hindered on a reefed main.

I had a 25ft mono with a 150 Genny on a rollerfuller. On my boat the jib was the power sail and the main was smaller (it was a 1976 - on most production boats today it is the opposite). Everytime I reefed the jib, my up wind perfomance was hurt because the sail shape was no longer as effective. The more I rolled it up the worse it got. I think about 130 was about all it could take. The AI is probably the same way - the more you roll-up the worse performance will get because of the sailshape.

Probably wouldn't hurt if we had sail tracks that would allow us to adjust the mainsheet position closer to the mast - maybe beside the seat.

Just my thoughts

Scott

Great thread!
I think one other factor might be relevant here. The mast is thinner in the top than at the bottom, therefore, more sail is furls around the lower part of the sail than at the top. When (strongly) furled, I found that I couldn't get the top of the sail tight, even on a reach the top of the furled sail is hard to keep from luffing, while the bottom already is (far) too tight. Sometimes my whole rig keeps "shivering"...
Scottr, I think you are right, it would be better to have the mainsheet position closer to the front in those conditions.

How would it be, if you could use the small sail on a really stiff mast in those very strong winds? The sail might be too small, but the shape (and effectiveness) could be great and the center of effort would be lower which is good in those strong winds... Anyone tried that out yet?

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skua

That's interesting Jerry, why's that?

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Chrisj,

You get excessive weather helm when the main sail is forcing your boat to turn into the wind. Loosening the sheet (also called a fisherman's reff) and letting the sail luff reduces weather helm but the sail is not pulling like it should and you are also putting excessive wear on the sail. Reefing the sail reduces the weather helm and allows you to adjust the sail properly.

You start burying the leeward ama when the wind is pushing too hard on the boat causing the ama to submerge. Again you can let the sail luff or reef the sail and adjust it properly.

Both burying the ama and excessive weather helm tend to slow the boat down. The down side of reefing the main is that you loose sail shape which means there has to be enough wind to overcome the loss of efficiency. The best solution would be to use a smaller sail when sailing on windy days but that's getting a little crazy but that is exactly what windsurfers and kite boarders do.

I wonder if my AI sail would slip on to my TI mast? The only problem is that my TI is yellow and my AI is red. Using the red sail on a yellow boat just can't work.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

Fair enough Jerry. I find I can control weather helm initially by easing the sheet, but if it gets to the point of the sail luffing, that's certainly an indication it's time to reef. I find using the sheet at first is handy in gusty variable winds, so I'm not continually reefing and unreefing. If the ama burying is the main problem, I prefer to hike out if possible, though I don't know how well that works on the TI.

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If you can ease the sheet without the sail luffing then you had the sheet too tight to start with which might be the crux of your problem. The easy way to properly adjust a sail is to let the sheet out until the sail starts to luff then pull the sheet in until it just stops luffing. If you can ease your sheet without the sail luffing you had it in too far to start with.

The next time you experience weather helm you might try letting the boat turn a little into the wind. As it turns eventually the sail will start to luff. Once it does, turn a little off the wind just until the sail stops luffing and you should be trimmed properly. If the boat still wants to fight you then it's time to reef the sail. Remember a little weather helm is normal and a good thing. It's like a dead man's brake on a train. If you let go of the tiller the boat will tend to head into the wind and stop.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

Keep going fellas, I'm getting alot out of this thread.
Your comment above is interesting skua, and is something that certainly make sense but probably not that obvious.

Back onto JollyGreens original thread, I'm wondering also about how wave direction can sometimes mask the true wind direction in either being influenced by tides, currents and bounce off headlands etc. When I first started sailing the AI at my local spot, I thought the starboard and port tack angles would be similar, but found that they were no way similar. I then realised that they were similar but it was because I was assuming that the wave direction was the same as the wind direction. Where I sail out we usually have easterlys and head out in that direction between two headlands. It's easy to assume the wind and waves are coming straight at you in the same direction but with bounce off the headlands and currents, this is rarely the case. Hope I explained it so it makes sense. Any comments ?

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Don't take life too seriously................it ain't permanent.

Yep, similar here on our side of Maui, the wind can change direction often because the wind is filling in round from the other side of the Island (were in the lee of the volcano) so wind and waves can be any direction in relation to each other.

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Hobie Island Sailing since 2006

Sailing most boats in windy conditions requires searching for the "groove" - thats the road to windward where the helm is light speed is max and pointing angle is slightly lower than optimum though made up for in speed to stay in the"groove " takes anticipation in the steering department. I've found the AI a bit harder than most boats to find and stay in the "groove" - reefed or not. You feel the power come on and the boat takes off but so far for me hard to maintain. The AI is a great boat and loves 15-20knots and I'll continue to search for that magic line, my advise is don't get hungup on pointing high just go for the fast lane.

Davew,

You are right. The AI is hard to keep in the groove. I found the TI is much easier. Last time out in my TI I was going to weather at 7 plus knots and was able to take my hand off the rudder control for several minutes at a time without the boat loosing speed.

Another good tool to use when going to weather is a GPS. You put in a waypoint for where you want to go and then watch the CS, closing speed, or VMG, velocity made good, to tell you how close to the wind you should be sailing. In sailing there is no free lunch. The higher you point the slower the boat goes but the more direct line you are on towards where you really want to go. Watching the VMG or CS (depends on brand of GPS) tells you what point of sail will get you where you are going the fastest.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

Skua - completely agree about the mast stiffness. My heart sinks a little everytime I see the top of the mast bend in a gust. The joys of unstayed carbon fiber. Flpside is it is a great safety valve.

Dosjers - please do try swapping out the mast on the AI and TI. The sail on the TI is larger - maybe to large for the AI.

ScottR

Scottr,

No way will the TI sail fit the AI and I wouldn't try it if it did. The AI is not engineered for that size sail.

One of these days I might try putting the AI sail on the TI when the wind is up it won't be anytime soon, though. I am about 45 minutes away from where I usually sail and I would have to make the swap before leaving home. Big problem is the wind is very diferent between the 2 locations.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

One other reason for poorer windward performance when reefed that isn't obvious, or atleast wasn't to me, is that it's the lift to drag ratio of the entire boat, not just the sail, that matters. Since the vindage from the hull and crew becomes larger in relation to the sail when you reef, it's only natural that the total lift to drag ratio of the boat suffers.

This would be true except since the wind is blowing harder than when you have the full sail out the lift you are getting from the sail ishould be just as strong.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

Jerry,

Is the diameter on the TI mast base larger then the AI mast base? I assume it is since the TI mast is taller then the AI.

Scott