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Just a couple thoughts. I've been doing some reading in trying to figure my M's poor perfomance in light air. I bought a book called "The Physics of Sailing" by Bryon Anderson. Just getting into it but it's interesting. It seems like Macgreggor had the right idea about the high aspect ratio daggerboard but I'm starting to wonder if the board is big enough. It turns out that a foil shaped high aspect ratio board is very good once the boat gets moving, but not good at all if the boat isn't going very fast because there isn't enough flow to provide proper lift. I also wonder now if the genoa is actually hurting me in light air as opposed to just a jib. At Chatfield the boat was doing just what Bryon says in his book. In very light air, a boat with this type of daggerboard will tend to just turn down wind. He also says that larger rudders can perform as an extended keel.

Leon, maybe you did good by getting a longer daggerboard?

It turns out that a foil shaped high aspect ratio board is very good once the boat gets moving, but not good at all if the boat isn't going very fast because there isn't enough flow to provide proper lift.

Is this the way Anderson said it or is it your paraphrase? It seems to me the conclusion ignores the fact that you need high lift when you're going fast, but less when you slow down. To carry that to the extreme, zero lift when you're stopped. So what's the problem? Maybe you don't want to "lose" lift quite as quickly as it actually happens in practice.

Bigger board = more lift, but also more drag, more space needed to store the folded (center)board, or retracted (dagger)board, higher draft, stronger, heavier, more expensive board, will change the rig balance, etcetera.

Most designs are exercises in optimization of competing parameters, and TINSTAAFL. I'd like my boat to be faster, but is a larger and/or heavier and/ or lead weighted board really the answer, and is it worth the time/ effort/ expense balanced against the above listed and probably other negatives I haven't thought of? Personally, I've decided not. Your opinion as well as your tolerance for expensive, time consuming experimentation that is as likey to lead to frustration as to joy may vary.

I also wonder now if the genoa is actually hurting me in light air as opposed to just a jib.

How are these two related? Less sail = less speed = less lift on the foils. I've never before heard it even hinted that poor low wind performance might be due to too much rather than too little sail. Anderson didn't say that, did he?

My own experience with my X w/150 genny, one on one against another boat on our lake, an X with jib only, I can literally run rings around him in normal winds. If anything, even more so in fairly light winds. I'd like to think I'm a way better sailor, but...

In no wind, I believe we're pretty much equal. Haven't ever competed in really stiff winds with reefed genny against his full, unreefed jib. I expect he'd beat me handily.

i just bought Sail trim, theory and Practice by Peter Hahne. I had many the same questions as BB about improving light wind performance after a poor performance at the Leukemia Cup by My beloved M. My book says the amount of drag produced by a 150 genoa is very detrimental upwind. It is nevertheless the engine of choice for abeam. He feels the poor sailshape for any sail furled more than 1/3 is just not worth it unless you are single-handed sailing. The roller furling luff is actually better than a hank-on. It just isn't much good as a "be-all" sail. He seems to say a much better combination might be a Jib and the assymetric spinnaker, which can be used with the main downwind, and for boats (like the Mac powersailors) are especially efficient sailing slightly off directly downwind. Symetrical spinnakers aren't as versatile he surmised, and can't be assisted by the Main. The tall skinny, high-aspect main is at it's best sailing upwind like an efficient narrow wind. I noticed the Corsairs often sail with a full-battened Main and no foresail upwind. I also read that the J-22 is about the best light air sailer on the planet.

He added some more comments about rigging saying the swept back spars with no backstays must be very taut to prevent forestay sag. He went on to say that the lower shrouds should not be tighter than the upper shrouds, for the same reason. I have also moved my rake aft a couple of degrees again, knowing it may cause more rounding up in heavy air, but allowing easier tacks in light air. Good trim I surmise is a total of subtle adjustments for the best current situation . I can't have everything at once, I suppose

I like the task accepted by some, using their inventiveness to enhance their Macs appendages. A weighted Board may enhance the marginal stability of the water ballasted MacGregor providing a stiffer boat with more drive. The benefits are yet to be determined as trial boards are still in the experimental stage. Im happy they are bold enough to share the results for our interest and thank them for being so generous, allowing us to view their progress first hand. Most of those moving to enhance their boat stiffness, sail in areas with medium to heavy air craving more than marginal performance and a manufacturers basic offering.

Testing The Set of Your Sails

Indeed Leon may have cut some of his longer boards benefit as it is so infinitely adjustable, in doing so he may have considered motoring and trailering. It's the back of your mainsail that works with your keel to provide lift when you are sailing to windward. It's critical that the leech stands straight and does not cup to weather.

I believe the M delivers more drive from its main, and would balance from a lightweight, well-designed composite. Mylar/Kevlar #3 Jib to sail in light air and still be able to hold shape when the wind picks up. Better if we had a drifter (very light nylon sail for boat speed less than 5 knots, anything more the sail can be damaged.) The X I believe develops more drive with its headsail and may suffer from sailing baldheaded. An old blown out, OEM genoa can be too heavy for the light stuff, so having a custom well shaped Mylar/Kevlar light air composite genoa, light enough to maintain drive in light air and hold shape when the wind picks up, producing drive, rather than rounding up with a poorly made, inexpensive bulk manufactured sail, too full and deep for anything more than marginal day sailing. Maybe a light air spinnaker poled out would work well in light air with the jib sailing on the wind.

Having a heavy #1 genoa too heavy in light air when a light #1 is not in inventory, could be improved with a light #3 able to fill and produce drive when falling off to keep the boat moving. In heavy air the #3 Genoa cannot compete with the #1 working jib because the MacGregors long spreaders and outboard chain plates combine to produce a poor sheeting angle with the genoa blocks for sailing close to the wind. Roller reefing produces at best a marginal sail shape, even if blocks could be set to power up or down the too full compromised sail, not to mention forestay sag and a lack of easily adjusted luff tension and windage created from furling.

Sails purchased for competition are expensive for day sailing. They benefit from being stored flaked and full length in a turtle to extend their useful life.and maintain their competitive shape,

Taking care of Sails

Care and Cleaning of Sails

Considering a "New Mainsail"

I have raced sailboats for many years and getting a boat to perform in light air is one of the more difficult and exasperating aspects of sailing. I frequently sail my X in local beercan races and learned quickly that in light air the Mac does poorly compared to most conventional sailboats. Fortunately the Mac does less poorly when there is more wind. Following the text book recommendations are all necessary but in my opinion secondary to not loosing directional control in the first place.

My best tactic for very light air sailing on the Mac is to make sure I keep the boat moving. Don't worry about whether you are on the preferred course, just continue to keep the boat moving. Don't let it stop. Once you let the boat stop good luck getting it moving again. In these same conditions most conventional sailboats will be well on their way before your Mac returns control to the helmsman.

Smart steering is the key. While you are grousing about the lack of wind carefully examine the big picture i.e. other boats, cat's paws on the water, smoke stacks and other indicators of what the wind is doing now ane what it may be doing in a few minutes so you can attempt to keep the boat moving and headed in the general direction of more favorable conditions. Pay particular attention to the rudder position. With wheel steering it is very very easy to turn them too far and stall the blades. This is a big no-no.


My favorite light air adjustment is the throttle setting on the Tohatsu.

normo wrote:My favorite light air adjustment is the throttle setting on the Tohatsu.

I have often resorted to the Iron Genny to help complete a tack...

normo wrote: With wheel steering it is very very easy to turn them too far and stall the blades. This is a big no-no.

Yes I'm pretty sure I did that trying to feel some pressure from the wheel during the race. I had to mark my wheel with tape to avoid repeating it. Good suggestions Normo.

Ive been hoping someone will bring a tiller conversion to benefit the feel of the helm when sailing

Is this the way Anderson said it or is it your paraphrase? It seems to me the conclusion ignores the fact that you need high lift when you're going fast, but less when you slow down. To carry that to the extreme, zero lift when you're stopped. So what's the problem? Maybe you don't want to "lose" lift quite as quickly as it actually happens in practice.

If you have the book it's on p 49. He clearly says that in low wind situations a larger keel is more necessary. Everything is a compromise. Too big a keel really slows down the boat when it's going faster but is better at slower speeds.

He also said that most sailboats will slowly drift downwind because of the lack of the keel to generate lift. Still the high aspect ratio on the 26M is favored for newer designs. To me this makes it critical that the sails be set properly in low wind. Otherwise the boat is uncontrollable.

On the Genoa issue: In the Dedekam boat on p 39 there is a troubleshooting section. One of the problems is too much lee helm. One cause listed is the main being too small relative to the headsail. The solution listed is to change to a smaller headsail. To me that says my problem is at least partly too big of a genoa in very light winds. A main that's not set right can cause this problem too.

The behaviour of a sailboat results from a lot of interacting effects that don't always scale equally with the wind speed.

I really recommend both these books. I paid $11 for one and $14 for the other on Amazon. They were used but in great shape.

My best tactic for very light air sailing on the Mac is to make sure I keep the boat moving. Don't worry about whether you are on the preferred course, just continue to keep the boat moving. Don't let it stop. Once you let the boat stop good luck getting it moving again.

I'm starting to believe this more and more.

In the lightest of air I have had better luck getting the boat moving (beam reach to close reach) by running the genoa between the upper and lower shrouds and then really sheeting it in hard getting the sail very flat.

A flat mainsail may also be in order for this condition.

Under 5 knts wind, drop the sails and turn up the throttle. It's no fun when the boat aint moving

Under 5 knts wind, drop the sails and turn up the throttle. It's no fun when the boat aint moving

You're disqualified!

Kind of disagree with the business about bigger foils in light winds. Easing sails right out till the boat has way and then not sheeting in too tight when it gets moving is a necessary technique to learn in the light stuff.

Over the years I've found that some people really have a knack in light breezes, and the rest of us don't. What's that maxim? 'Anyone can sail a fresh breeze'.

One thing that hasn't been discussed in this thread is the boat shape. I've only had mine for one season, so this comming summer will sort a few things out for me, but I can't stop looking at the hull shape and wondering. Displacement sail boats have rocker; the Mac does not. Our tuck is always in the water, and there is always turbulence there. Turbulence equals drag, and I'm starting to wonder whether - at least under most sailing conditions - the Mac doesn't have the horsepower to break through.

For many years I sailed a light displacement 16' trailer sailer with hard chines. The accepted practice in light breezes was for both crew to move to the leeward side of the boat. This had the following effects:

- The sail shape is maintained by gravity, so all the energy of the breeze is used as drive

- Heeling the boat to extreme angles exposes less surface area to the water; less drag

- The boat ran on its chine, which effectively becomes a rail that resists leeway

This isn't possible with the Mac unless you have a few people, no ballast, and some sort of running strake that is only in the water when heeled. I also suspect that the enormous amount of freeboard on the Mac is a bit of a problem in light air.