Heavy weather-sailing under main only

[delevi]

This probably is specific only to the boat which can sail on main only... based on various comments from owners that the must have both sails at all times.... so here it goes.

I have found that when the wind and seas get hairy, talking 20 kts or more, any headsail just kills the helm and tracking ability. This does not apply to a close beat, but all points of sail from 65 degrees to the wind and lower. The boat just wants to go to windward, even when on a broad reach, even with just a small amount of headsail up, though not as bad. From what I have found, the less headsail, the better. I want to be clear that this is not from wind alone, but a combination of wind and waves. My theory, and this is only a theory, is that the boat is tripping over its own bow, probably because the bulk of the ballast is in the front 1/3 of the boat and the daggerboard is in the same position without any longitudinal rake aft but rather straight down. What I think is probably happening is the headsail exacerbates this issue, due to the shape/weight distribution of the hull & foil. By dumping the jib or genoa, the forward force is alleviated and the bow perhaps rides higher. I have experimented with various sail configurations in the conditions described. Beam reaching with some headsail up is controllable though constant helm corrections are needed. Broad reaches in quartering seas essentially made it impossible to control he boat under main and jib. So, I decided to roll up the jib completely and use anything from a full main to 1st or 2nd reef, depending on wind velocity. I was pleasantly surprised that the weather helm almost completely disappeared and the boat tracked much better. I managed 6 knots consistently in 18-22 kts breeze 80 degrees off the apparent wind on a double reefed main. Heeling was 15-20 deg. I could have gone up to the first reef but it's been a long full day of sailing and I was quite tired, so I just kept sailing this way all the way down to the marina entrance. On other occasions, I have sailed on broad reaches on just a single reefed main with 25-30 kts wind and 3 foot waves (closely spaced) pounding on the stern quarter managing reasonable control, hitting speeds between 8-10 kts. This would not have been possible with both sails, based on experience in the same conditions with both sails….. boat constantly spins out 90 degrees to windward as if the rudders weren’t even there.

Leon

[beene]

Ok, I follow you.

Just one question..... when you say

This would not have been possible with both sails, based on experience in the same conditions with both sails….. boat constantly spins out 90 degrees to windward as if the rudders weren’t even there.

...... was your drink in your right hand or left hand.... or was there one in both..... LOL

Just kidding L



G

[Love MACs]

So the lesson here... is not to put one third of ure ballast in the bow Was that done on purpose or is it just due to the weight, mods, storage u have put there? Or rather are u trying to say that you should just not use a headsail in 20+ knt winds? Not being sarcastic, just a learning question.




Allan

[ronacarme]

Not so ....that X must have both sails up at all times.
We have had our X for 8 years. This year for example I have sailed maybe 25% of the time with full main only. Our X, flying full main only, balances the helm well with about 40% of CB line out, and sails nicely on all points of sail, given enuf wind to keep boat speed above 2-3 mph. The idea is that the main-only center of effort (CE) position is spaced aft of main plus jib CE position, which for helm balance needs the hull's center of lateral resistance (CLR), and hence the CB, corresspondingly shifted aft ....and partly raising the CB swings its center aft, as well as up

In winds so high as to require tucking the factory reef in the main, the sail area (reefed main only) is not much larger than the lateral area of the hull and rigging, and the boat does not sail well to windward. Adding the little 25 sq ft storm jib, flown well above the deck on a 4-5 ft long tack line, seems to improve air flow over the reefed main and improve sailing to windward.

[delevi]

Allan, I am referring to the majority of the ballast in the Mac being centered in the front 1/3 of the boat, as well as the location of the daggerboard being in that same spot. This is not just my particular boat. The boat is much lighter from center aft than in the front. The only difference in my boat is I have an additional 150 lbs ballast at the bottom of my daggerboard. I am not saying not use your headsail in the conditions mentioned, though through much trial & error I have found this setup to work best for me. I also had some discussions with the dealer who is on SF Bay about this and he concurs that the boat sails better on reaches with just the mainsail when the seas are rough... so most likely my weighted keel isn't much of a factor here. Also, I have tried pulling up the keel when sailing on broad reaches, which actually helps the boat maintain its course. Still, I believe this alleviates the affect of the boat tripping over its own bow and/or keel rather than just the small increase in ballast my boat has. Again, I can speak for actual performance results and only formulate a theory as to why it happens. Would be nice to have someone chime in who has a good understanding of hydrodynamics as it relates to boat design.

Geoff,
I never sail with more than one beer open at a time, unless I forgot to finish the last one and opened another one Hey, I only have two hands

Cheers,
L.

[delevi]

ronacarme,

My bad. Just going on what I read in the past about the and both sails. Never sailed on one myself. I completely agree that when going to windward, you need some headsail. I don't have a storm sail, but simulate one with the jib furled 3/4. Once off the wind, however, in nasty conditions, the jib just seems to kill performance.

[bubba]

Ballance from bow to stearn is indead important so I put my banjo and dobro with there heavy cases in the aft birth when sailing and we also use our stern rail seats for added ballance. Keeping everything stowed lower than the dinnet table is important for healing control. We enjoy sailing in 0 to 40 mph wind and have found our M very stable in 5 ft wind waves with 3 reefs on the main to choose from and when needed we also have a reefed 110 jib , gennaker or A-spinnaker 350sq ft and down wind spinnaker 400 sq ft.

[beene]

Geoff,
I never sail with more than one beer open at a time, unless I forgot to finish the last one and opened another one Hey, I only have two hands

Thanks for clearing that up L.

However, you do have 2 drink holders convenintly close to the helm.......

G

[AWKIII]

One way to balance the boat's sail plan in higher winds is to use a storm jib. We offer two models: one with hanks and the other has #6 tape for roller furling systems. Price is $195.00 for both.

With the storm jib up, you can use the main at 100% or reef it. You will find this combination of sails will make a big difference.

[Indulgence]

Art- Can you use a storm jib with a roller furler?
I've seen examples that sort of wrap around the
furled sail but that doesn't look like something I'd
want to try deploying after the storm comes up.

[bubba]

One thing to think about when using the standard 110 jib furlled is to not tighten the jib sail inside the bowrail when going to wind, It is too easy to over tighten the furrled jib and put the boat in irons. I dont know if the shape of the 150 jib can be furlled into a storm jib. I do know that the 150 jib does not point close to wind by about 5 to 10 deg's compaired to the 110 jib.

[AWKIII]

Indulgence.

There are a lot of different storm jib designs for roller furling systems including the one you mention.

The one we build has #6 luff tape just like your roller furling jib or genoa.

If the wind is up, just take your jib/genny off the extrusion and install the storm jib. It can be furled and unfurled just like any other headsail.

Art

[Hamin' X]

My reasoning here may be flawed and anyone is welcome to correct it, but I see what you are doing is only masking a problem, Leon. The way I see it goes like this:

When you are sailing under main only, you are placing the boat out of balance. You are moving the center of effort aft. To counter this, you need to move the center of resistance aft as well. You accomplish this by raising the dagger board. However, by doing this you are reducing the overall resistance of the boat to making leeway, while at the same time reducing the heel angle of the boat due to less resistance from the dagger board. The illusion is that you are now more upright and are pointing higher into the wind. The fact is that while your heading is more in the direction that you want to go, your actual direction of travel has fallen off due to the increased leeway.

Of course this is only speculation on my part and I have no empirical data from your boat to confirm it. The only way to find out is to use a GPS unit and check your Velocity Made Good toward a given target. This may be difficult in SF Bay due to the variability of the currents. You could try it on a slack tide and maybe in an area where the river outflow currents are minimal.

Anyway, it sure sounds like you're having fun.

~Rich

[Currie]

Hi Leon,

I'll throw in my $.02 FWIW....

I don't get the same behavior with my factory sails. It seems strange to me that dropping the jib would decrease weather helm rather than increase it. I defintely see the opposite with my M. I can only think of two reasons why it would happen....

1.) Losing the jib drops a major amount of weather-helm-inducing heel....or
2.) Your waterline stance is too bow-down.

FWIW - I can't see #1 happening on any point of sail (just scribbling some lines on paper). I'm suspecting number 2. I just added an electric head and supply-holding tanks to my M that added about 100lbs to my forward area. I noticed the difference the first time out. I definitely didn't motor or sail as well. I could see the difference in the waterline and feel it as well from the cockpit. I tucked two 40lb bags of softener salt under the rear berths but I think I could use another 80lbs to compensate because the bow has much less bouyant area (and so dips down more easily). Looking at the factory drawings my eye puts the front/back center-of-bouyancy about 1' in front of the ladder base. What I'm wondering is: did your 150lb daggerboard take your bow-down an inch or two - causing too much "bite" as you describe? Do you have any pics of your boat in calm waters with a couple of sailors on board (so as to look at its waterline stance)?

Just a thought - let us know what you come up with.

~Bob

[delevi]

Rich,

Your point is quite sound and follows all basic principles of sailing, however.... we're not talking about pointing here.... rather off the wind sailing. Leeway is not an issue with the board half way up on a beam reach or lower. You don't need as much board for those points of sail. In fact, the Mac M manual recommends to lift the board half way on a beam reach and 3/4 up on broad reach, all the way up on a run. Also, the Mac is different animal and handles differently from most conventional sailboats. With enough wind, the boat does not feel out of balance at all with just the mainsail. On the contrary, control is much more stable and easier to control, even if we take the daggerboard out of the equation and leave it fully deployed. Again, we are not talking about pointiing here, which absolutely requires some headsail. Also, many of you may not have experienced the sea state I am referring to. You typically won't get it on a lake, and maybe not in open ocean. Swells are one thing. Sharp 3 foot waves/chop closely spaced together are quite different and seem to be the most difficult to navigate in on the Mac, especially when combined with ocean swells. San Francisco Bay is a challanging place to sail.

Currie,

You may have something here with point #2. The problem seems to come from too much bite on the bow. It's not a problem when pointing but when reaching the boat seems to trip over its front section as a wave hits the beam and or stern, causing it to spin out to windward. Somehowe dropping the jib just makes it all better. Not sure if the 180 lb keel is the culprit or whether this is just the characteristic of the Mac M hull desing. I had the weighted keel for some time now, but if memory serves... I think this characterisic was always there, prior to the Mod. I may be wrong. Suppose one way to find out is to put the stock board back in... but a major PITA to make the switch.

Forget theory for a moment and next time the wind kicks up to 20 knts, try rolling up your jib and use the full main (flattened or perhaps on the first reef if you have one.) Then sail on a beam reach for a while. Then roll out part of your jib. I'll bet you like the main-only config and probably go faster.... unless my setup is so screwed up that I'm the only one experiencing this issue.

I'll try to take some pics with the boat on the water ballasted up. Not sure if I want to remove the weighted keel to experiment.... the boat just sails better with it on my pond which is why I got it in the first place...... but maybe when I get some extra time on my hands

Cheers,
L.