What Makes a boat point well?

[Janusch]

Still to cold here to sail so just daydreaming about it. I was wondering if any of you know what makes the differents in a sailboats ability to point? Is it the location of the center board or keel? Free board? Sail configuration? I personal don't have a clue, but I know there are some pretty good engineers on board here so ... why?

God Speed
Dave

[Mark Prouty]

That guest was me.

[craiglaforce]

I'm not a racing expert or anything, but I've found that taking all but a little weather helm out is helpful, as well as using the standard jib and playing with the sheet block location and tension. Steer and adjust jib trim by the sail telltales as they are the first indication of non-optimal heading or sail adjustment. You want them all to stream straight back or nearly so. A good tight forestay (turnbuckles) and full tight hoists on the sails helps.
Mainsail shape tweaked by halyard and outhaul tensions to match the wind force and sailing angle.

One reason keel boats tend to point a bit higher Is these boats tend to be more stable and hence the sailplan is held steadier not wasting wind or stalling at every little wave. Also, although the long thin centerboard is supposed to be more effient, I think it is a little more touchy to keep it from stalling. Then you lose the only thing constraining the boat to go upwind and tend to make leeway (slide downwind).

One year I had the boat pointing to 45 degrees of true wind (tack through 90 degrees) but then I installed new sails whcih changed sail CE and I only retuned once quickly for the season plus and got a 10 inch crack on the centerboad which probably didn't help much and last year it was back to 100 degree tacks.

With the genoa I could not point the thing worth a darn and now use it sort of like a spinaker, flown free from the spare jib halyard going mostly down wind although it works OK on a beam reach when flown this way also.

Basically you want good fairly shallow air foil shapes on the sails set at the angle of attack to the wind just before the stall angle, which provides the lowest drag laminar flow across the sails.
You want the hull to maintain a steady heading with minimal rudder angle, be steady and present minimal drag in the water and the wind. The hull should also be able to stand up to a stiff wind with a tall aspect ratio rig to give better sail efficiency. THen its a lttle trial and error a little science and practice to see what is the best for your conditions. If you are learning it helps to get behind a keel sailboat that looks fast going upwind and try to match their heading and sail trim.


I'm sure someone here has some racing experience and can give you some more ideas.

[Duane Dunn, Allegro]

The more I read about this the more I think a big part of the pointing issue with an X is the hull shape. Our hulls are a non-balanced design. A balanced sailing hull keeps the same volume fore and aft as the boat heels with little tendency for the bow to depress. This stops the center of lateral resisance from moving forward. When the center of lateral resistance moves forward you get a increase in weather helm. The design of our hull is such that the more you heel the more the bow drops due to the fat stern with lots of bouyancy. This directly adds to weather helm. We end up having to counter this by pulling the centerboard up to move the lateral resistance back and get balanced with the sailplan.

Given that we can't change the shape of the boat we will always get the best performance and pointing if we reduce sail early to limit heeling as much as possible. Keep the boat flat and you will gain quite a bit of pointing ability.

[Dimitri-2000X-Tampa]

That's a good explanation Duane. I'm just starting to understand how much weather helm has to do with things on this boat. Besides causing extra drag on the rudders which are trying to compensate for it, raising the CB to move the CE further aft is contrary to good pointing ability where you want that board as deep and straight as possible to minimize the downwind drift. I can see why many of you have gotten shorter forestays now and I'd be curious if anyone with a shorter forestay and less weather helm has ever raced a stock boat.

Another trick is to pull the boom to the windward side like you would do with a traveler...I've read about people on this board with the X who clip the mainsheet onto the windward stanchion...although I've never personally tried it. Beating into the wind doesn't seem to be a crew favorite. Waves definitely slow this boat down a lot more than heavier keel boats. I frequently watch my GPS jumping instantaneously between 4 and 8 mph when waves are involved.

I also agree with Duane about minimizing the heeling. You could actually go fastest with reverse heel (like a windsurfer for example) although would be a bit impractical on a Mac .. without a cow on a trapeze anyway. I've only reefed my rig once and I did it at the dock before going out. As it was my first time, it took me a good 20 mins to get it done and it would be a pain to do in 20 mph winds and waves, thats for sure...hence, if it gets real windy, I often sail with a furled genoa only...which isn't too good for pointing so I end up staying on reaches instead.

Are there any good tricks to efficient reefing with the stock mainsail? (I know, get a single-line reefing system) I probably didn't go about it the best way as I use a line around the mast as a sail-slug stopper (ever since my brass stopper went overboard the first time I took the boat out). To be able to hook the reef grommet, I either have to remove the slug stop and let everything fall out, or, what I ended up doing instead was removing one of the slug shackles to give enough slack to hook the reef point. Once it was hooked, I tightened up the outhaul and then looped it around the mast and through the holes. Not very nimble to say the least.

[Duane Dunn, Allegro]

You need your slides on a jackline. This lets you leave the sail stop in place and still get the grommet to the hook when you lower the sail. Keep a line in the rear grommet and you can reef in under a minute.

After loosing one sail stop in the drink, I now have a tether on it. I just used some heavy mono with crimps to put it on a leash hooked to the boom.

[Dimitri-2000X-Tampa]

Great idea Duane, although I only have one grommet/shackle per sail slug, not two like shown in the pic. Wonder if that will make it harder to pull the sail close to the mast with the jackline. I guess its best to run the jackline through 2 or three slugs....I'll have to give it a try.

Can't quite visualize your tether set up. Mine is about as simple as it comes, loop a 1/4 inch line around the mast and the tops of the sail cleats a couple times, put a couple hitches in it to secure it and I'm done...I probably have enough extra line in it to use as the jackline. What is the top of the jackline secured to, a sail grommet? Wouldn't think you would want to put much tension on those little plastic shackles.

As for doing it in under a minute, you must have a lot of practice...don't you have to go up on the cabin top twice to reef (first to hook the reef grommet and then a second time to wrap the line around) or am I missing something?

[Duane Dunn, Allegro]

The jack line is tied off in a grommet top and bottom with a stopper knot. When the sail is hoisted full the line goes taunt keeping the slugs on the jackline tight to the bolt rope. Lowering the halyard puts enough slack in the jack line that you can pull the reefing grommet to the hook without removing the sail stop at the bottom of the track or releasing any sail slugs from the track.

It's best to have each slug captured between two grommets as shown in the picture so the proper spacing is maintained.

If you already have the line in the rear reefing grommet it's a simple and quick process.

Step 1 - You go to the mast only once, lower the halyard to get the grommet on the hook, then hoist the halyard to tension the sail back up, cleat. (I'm assuming you have a topping lift or boomkicker/rigid vang to hold the boom up while the sail is lowered.)

Step 2 - Go to the back of the boom and pull the line and cleat on the outhaul cleat.

Done, you may want to tie some light line through the middle small grommets to keep the loose sailcloth out of the way, but these do not take any of the load. That line can be pre installed with a knot on each side.

The teather is just to keep from dropping the sail stop over the side. It is just about 18" of heavy fishing leader with loops on each end made with crimps. The one loop at the sail stop end goes on the threaded rod between the slug that goes in the track and the thumb nut. THe other is just on a ringding on the boom. Now if I fumble finger the stop it can't go swiming.

[Bill at BOATS 4 SAIL]

If the sail-slugs are spaced correctly, you do not need a jack-line.

[Duane Dunn, Allegro]

Bill,

I'd love to know the correct spacing. My sail has the slugs sewn to the bolt rope. With the sail stop as low as it will go there is still no way I can get the reefing grommet to the hook. What are the dimensions I should sew them at so I can reef without having to take them out of the track yet still not have a loose floppy sail at the mast.

I should mention that the Bluewater Yachts approach with the jackline is added to the sail by a local loft that also puts in an intermediate reef as well. The jackline lets you use either reef without removing the slugs and lets you put in single line reefing in conjuction with halyards aft so you don't even have to leave the cockpit to reef.

[Dimitri-2000X-Tampa]

Duane, thanks for all the great responses. One thing which I've been doing a bit differently (I suppose due to my windsurfer past) is that I always tighten the outhaul first, before the downhaul (main halyard). I was taught that this was the best way to get all wrinkles out of the sail and get it as flat as possible (what you want when you are reefing in the first place). So, that is why I had started from the rear of the boom, and then tighten the main halyard later. Not sure if that is the best way and of course, maybe I'm just wasting my time with a Mac sail anyway since the stock ones are not exactly high performance. I'm also curious as to what Bill has to say about sail slug spacing since mine are obviously not spaced right either...kind of hard to fix after the fact though.

Shock, thanks for the post, that is one of the best explanations of sail trim I've ever seen on this site...I hope you stick around, we may sail hybrid powersailors around here, but we all share the same love of sailing...and true sailors are always wanting to learn new techniques. I know what you mean about the furled genoa not pointing very well. Our boats actually come with a factory jib which sheets in at a different pulley (further forward and inside on the cabin top) which performs better in these situations...however, I usually only have time to perfect things on the few occasions I get to go out alone. The furled genoa is the king of convenience though.

[Duane Dunn, Allegro]

Dimitri, at least my slugs have been attached with what looks like whipping thread and I can move them. Sounds like your's are in grommets. You might do better to just add a second set of grommets and put on the jackline.

Schock, Where abouts are you? I'm sure we have someone with a Mac nearby. I've always wanted to take someone out on my boat who really knew sailtrim and could show me the best way to get the most out of what the Mac has to offer.

I'm in Puget Sound.

[Duane Dunn, Allegro]

It's interesting that by his handle, 'Schock Therapy', I assume Schock is a fan of their boats. The Seattle MacGregor dealer, BlueWater Yachts has also sold the Schock line right beside Macs for many years. They have since cut back to only doing the Harbor 20. Todds (the owner) wife Cheryl raced a Schock 35 for many years in Puget Sound including the Puget Sound Sailing Championships with her boat.

We'll be out next week, looks like we'll launch in Everett and spend 4 days over in the Port Townsend / Port Ludlow area. The kids enjoy Fort Flaggler alot. Looks like the weather will hold nicely.