Imagine A Powersailor design unconstrained by cost

[Wayne nicol]

remembered where i found it- jeesh- it was over 2.5 years ago- cant be crazy yet
look on this web page, first page where it says "sprit sails outperform bermudan"
it is a link to pdf files, so they take a bit to download- but i dont know how to give a link to them directly- sorry!! techno -peasant!!
http://www.christinedemerchant.com/sail_sprit_sail.html

[mastreb]

The Gemini's and Lagoon's have been all over the globe, and those guys will tell you that they are more comfortable than a similar sized monohull and are safer because even when flipped they float and are designed to be liveable when inverted. Also, they will tell you they're safer because they aren't hauling 10,000 lbs. of lead trying to pull them straight to the bottom.

I'm a big fan of multi-hulls, having crewed on and nearly bought a 28' Corsair instead of a Mac, and I'm going down to Cabo with my brother-in-law to look at a Gemini 3000 with him. Certainly they're more comfortably livable in fair weather than a multihull, and they're safe passage makers in good weather.

But I've also lived on the ocean full time for over three years, and transited in storms including hurricanes (because my Captain was not a gentleman, and he did beat to weather). 90% of the time, a catamaran would be absolutely fine and fun. 8% of the time it would dicey but okay, and 2% of the time you'd be living in it upside down. I personally don't consider floating in a flipped catamaran to be anywhere as seaworthy as a monohull that would have survived the same storm intact.

To your point, no pleasurecraft should be subjected to that weather intentionally, but if you're living on the water long-term, it's going to happen.

Joshua Slocum did a solo circumnavigation and lived a decade after in a boat that we now know from reconstructions and analysis was critically flawed in its angle of vanishing stability. He disappeared in it during a relatively simple transit to Brazil. Why? because not being seaworthy will eventually kill you if you live on the sea.

MacGregor's innovation of seawater ballast is the best possible compromise, but the boat still doesn't point as well as a full keel boat by any means.

You mean it won't track as well, right? Pointing ability usually comes from high aspect rigs and long deep pointy boards/keels. Full keel or 3/4 keels will track well in a straight line, but won't get you to the windward mark in as few a tacks.

I mean it won't point or track as well. Despite having fin keels and medium aspect rigs, MacGregors do not point nearly as well as the same rig would point with a full keel. I've measured my pointing in the MacGregor and know what my similarly rigged Columbia Sabre could do, and there's no real comparison.

The retractable boards also contribute to this problem. The keel is limited in size, length, and weight in order to accommodate trailerability, which limits its ability to balance sail power and thus limits the amount of sail you can loft. You cannot put a lead bulb in the bottom of the daggerboard because it would cause roll instability when powering.

Trailerability limits a boat to a practical maximum of about 32 feet. That's a bit too short for two complete cabins, but you could probably pack eight people into it. It would be tight.

The only constraint to trailerability is beam, not length. Beam is limited to 8'6" in order to be legally towed on federal highways, and it's less than they in some states. This thing is trailerable, keeping in mind you're gonna need a pretty hefty tow vehicle, like a dually, but it's trailerable:

http://www.containeryachts.com/

And again, it's not the length or weight that sets the limits on pulling it, it's the beam.

I've seen that containerable boat. I like the idea. Yacht designers build to relatively specific beam-to-length ratios to achieve various goals, with wider beams being generally more sea-kindly and narrower beams being generally more seaworthy. Being far outside those ratios creates new problems, and being exceptionally narrow for a given length, like that containerable boat, creates a boat that is fast but tender and which heels extremely. It's not unsafe, but it's not very comfortable for the crew, which is why most boats these days are exceptionally beamy: They're trading speed for comfort.

Other practicalities include loading and launching from the trailer simply, and the tow-beast. Beyond 32 feet, you cannot stay below 10,000 lbs (the towing limit of a consumer truck) without going to extremely exotic materials.

That's why I called it a practical limit, not an absolute limit.[/quote]

safely off-shore capable

This is not really possible for an ultra-lightweight displacement boat. You need a relatively heavy boat to be seaworthy, as lighter boats have movement characteristic that are exhausting in heavy weather even when they aren't unsafe. Size is also a practical matter: The bigger a boat is, the bigger the seas it can survive. The smaller you are, the more likely it is that a storm can overwhelm a boat. The biggest problem is that the smaller foils below the waterline cannot compete with a full keel in terms of seaworthiness. They don't track straight with a light helm and they remain tender, being tossed about by seas that a full keel boat could ignore. Finally, the flatter stern required for powering increases tenderness and the tendency to broaching in following seas.

Again, these seaworthiness characteristics require a full keel, a deep draft, and a heavy displacement. You won't match them with the compromises required for trailering and powering.

So, I think Roger M., Steve Dashew and the Volvo 65 along with myself totally disagree with this. The counter to this is that speed is safety. Getting out of the way of a storm is much safer than trying to weather through it. And no boat can ignore heavy weather, as should no crew. A planing hull like the Volvo Ocean 65 with water ballast and multiple water tight bulkheads is infinitely safer offshore due to it's positive bouyancy and it's ability to close off a damaged section of hull and to hustle away from weather rather than trying to slog through it.

I'm specifically talking about trailerable boats, which don't include the Volvo 65 or the MacGregor 65's or 70s. The MacGregor 26 is not an ocean cruiser and isn't intended to be.

While the Volvo and big Macs are ultralight in terms of ratios, they're still very heavy boats with displacements in excess of 30,000 lbs which make them very fast. The larger a boat is, the more survivable it is, full-stop, and these very large boats can be ocean worthy at ultra-light displacement ratios.

But no boat under 10,000 lbs. displacement is rated CE: A-Ocean. The absolute minimum requirement is 6600 lbs, but the Angle of Vanishing stability requirements include displacement (130 - (2x mass in tonnes)) and make it nearly impossible for a light boat--especially a lightweight sailboat--to pass.

These ratios aren't just numbers: They're derived from the insurance records of boats that have been destroyed at sea to develop algorithms that describe the boats that sink vs. the boats that are destroyed. They're literally centuries of experience encoded as algorithmic rules.

Now again, this is absolute mass, not mass/displacement ratios, so big ultra-light displacement boats pass just fine. I suppose I should have been more specific about that in my original post, but I was already going long [/quote]

Gaff rigs don't point as well as a bermudan rig, BUT ultralight boats don't point anyway, so you'd do just as well with a gaff on these boats as a bermudan. Furthermore, gaff rigs perform better on all other points of sail, which are the points that these boats sail on. This is a "no downside" design that I'm very interested in.

Again, this isn't correct. First, a fin keel with a long thin rudder will out point a boat with a full keel. Think about it this way, two 24 ft. sailboats, a Moore 24 and a Pacific Seacraft Dana 24. Who will get to the windward mark first? The Moore, hands down. The Dana is going to maintain more forward momentum in a chop because of the increased displacement, but will not be able to point as high into the wind. Gaff rigs are also less efficient and generate less power due to the shape of the sail and the fact that the spars interrupt airflow over the sail surface. Gaffs were used back when sail cloth was much heavier and more leverage was needed to control and lift the sails. Lightweight sail cloth has made them a thing of the past.

A very high-aspect ratio bermudan with a fin keel will outpoint anything, but that doesn't mean it's ultra-light. Ultralights skim across the top of the water like a plate with very little wetted surface. That reduction in wetted surface also reduces the ability to resist rotation when pointing. The simple fact is that MacGregors, an ultralight displacement boat, do not point particularly well and if you've got the huevos to sail one without ballast, they point even worse. Check out CA Marchaj's book "Sail Power" and read the chapter on ultralight pointing performance from tested examples. It's quite persuasive.

I disagree regarding Gaff rigs being a thing of the past. There are good reasons, especially in smaller boats, to have a forward mast as allowed by a gaff rig. It gets the mast forward enough and low enough that it can be lowered without unstepping, which is a huge practical advantage for trailer-ability. Short-gaff rigs with a good foresail are faster on all other points of sail besides pointing, and that why they didn't require an entire closet full of foresails to change to for broad reaches and running the way a bermudan rig does. The fact that they're out of fashion means very little to me, and there's been very little research done to how they would actually perform when made of modern materials.

Large roach fully battened mainsails are little more than modern gaff rigs anyway, and they're beginning to dominate the cruising circuit for this exact reason: Better light wind and beam wind performance.

What I'd like to see Tattoo build wouldn't really be trailerable, but a 42+ foot boat, with a plumb bow and a wide flat aft, with dual retractable rudders and canted daggerboards, not lee boards though. I'd want water ballast and positive flotation, and for it to be beachable. I would also love to have a kick up out board underneath the table in the cockpit, so no unsightly motor is hanging off the transom. I'm really bad at estimating, but I would think a 110hp would be able to drive a boat like that at 20 knots with the ballast drained. The idea being, like you said, to dump ballast and run if things got hairy. I'd also like intergrated pads for a large radar arch, as a big mount for davits and bimini and solar panels.

I was really supposed to be working today, but this is much more interesting.

I'm ready.....flame away!

Hey I'd love to have a boat with zero compromises too! Sign me up! A boat of this size however would require a commercial rig to pull it, which puts it outside the realm of my desires. Some very cool ideas, however!

And I certainly do enjoy a rousing conversation about boats.

[J--]

Sorry it's taking a while for a response.....that whole pesky work thing.....

I mean it won't point or track as well. Despite having fin keels and medium aspect rigs, MacGregors do not point nearly as well as the same rig would point with a full keel. I've measured my pointing in the MacGregor and know what my similarly rigged Columbia Sabre could do, and there's no real comparison.

So, those are two pretty specific examples, and I'll address both. So, your Sabre (pretty boats BTW) is not really a fully keel boat in the traditional sense. It's built sort of like one of the J-yachts, which had a cutaway fore foot, and the rudder was integral to the keel. This wasn't a particularly deep drafted boat either, drawing about 4 1/2 feet. These boats were also built to some odd rules that penalized waterline lengths, which is why boats of the era had such lengthy overhangs. So, not really what I'm talking about when I'm talking about a modern hull with a high aspect rig meant for racing to the windward mark. Think like a First20 or a J/22, and I am limiting to trailerable boats. Either of those two will be able to point higher into the wind than the Sabre with a similar water line length, and that has to do with first, a deep draft for the length, in this case, about 4' for the J/22, and it's 10 feet shorter than the Saber! The closest J in length to the Sabre is the 97 and it draws 6 1/2 feet of water. The J/100 draws just shy of 6 feet, and both boats are roughly 32 feet long. Ok, so what all this means is that boats with longer, deeper foils under water are generally going to be able to point higher in to the actual and apparent wind better than a boat with a full keel. This kinda leads me to the problem of centerboards. Moveable centerboards, depending on their shape and size can be every bit as effective as a fixed keel, but in many cases the shape, size and position of the centerboards and their trunks are compromised for interior space. I believe this to be the case with the Mac26's. I think that the centerboard is too far forward to be as effective in pointing as it could be. Also, as all keels are essentially a wing under water, a more efficient shape is also going to improve windward performance.

All sailboats slide to leeward as they sail. It's called leeway. Full keel boats have much less of it than boats with fin keels do. Simply because there is more surface area resisting lateral motion on a full keel than there is on one of the pointy fins. I'll take a bet, and feel pretty confident in my odds, that the Mac gives much greater leeway on say a beam reach than the Sabre does.

One of the complaints about the newer Macs by the polished teak and carbon fiber crowds is that they are not "real" sailboats, which I say is hogwash, they have a stick thing and a cloth bit and can still go when the motor is off, and those are all the qualifications one needs for a sailboat. The thing that is accurate about the Mac is that it wasn't designed to go around an imaginary triangle in the water, and since all engineering is compromise, the absolute upwind performance to the windward mark gave way to a comfortable interior, and a hull shape better suited to comfort than to sailing speed.

But no boat under 10,000 lbs. displacement is rated CE: A-Ocean. The absolute minimum requirement is 6600 lbs, but the Angle of Vanishing stability requirements include displacement (130 - (2x mass in tonnes)) and make it nearly impossible for a light boat--especially a lightweight sailboat--to pass.

Yeah....no. You're now saying that the Flicka and Contessa 26 are not offshore capable boats. Um...no. Even if we're sticking just to mono-hulls, and I get that CE certification wasn't really invented till the late 80's but still.....you give me a Flicka and my @ss is outta here!

Beyond 32 feet, you cannot stay below 10,000 lbs (the towing limit of a consumer truck) without going to extremely exotic materials.

Hmm....I don't know what kind of girly state you live in , but here in the Lone Star State, we can buy trucks that will tow 30,000 lbs. (Ram 3500) and have a total vehicle length (truck and trailer) of 65 feet. So that 39 foot container yacht becomes a "trailerable" boat. You only need a class B license if you go over 26,500 lbs. total. Ok....so, all kidding aside, that's a little extreme, but my point is though trailerable is probably much bigger than you'd think. Easy to launch? Ok. I'll concede 26 is probably the max here.

Large roach fully battened mainsails are little more than modern gaff rigs anyway, and they're beginning to dominate the cruising circuit for this exact reason: Better light wind and beam wind performance.

I gotta disagree here again. A roachy main main with battens isn't near the same as a gaff. Battens run horizontally to help the foil shape of the sail and a larger roach in the cut increases sail area. A gaff has the same horrible problem that lateen rigs have: performance on one tack is much better one side than the other because the gaff interferes with the flow of air around the sail. Had you said junk rig, I might have believed you, not a gaff.

Admittedly, the only gaff rigged boat I've ever sailed is an Optimist. But really, if the gaff was a faster, more efficient rig they would be used on Lasers, Hobies, Melges, J's, Colgates, Ensigns, Farrs, 420's, Macgregors, Santana's...etc. But they're not.

[Wayne nicol]

im trying to learn here- and not wanting to rile good folk,but all the talking and reading i have been doing- and recently i have been spending a fair amt of time talking to NA's
but i think that the high aspect bermudan may be faster around "the imaginary triangular route" than some of the square/trapezoid shape sails, but are only truly faster when pointing, and are only comparable on other points when they are running jibs, and have vastly increased sail area.
normally the trad rigs are faster on all other points of sail!!

i did post the results of that test i dug up- it seems a reasonably fair test- and the results were a little surprising to me too!!!

quote
"remembered where i found it- jeesh- it was over 2.5 years ago- cant be crazy yet
look on this web page, first page where it says "sprit sails outperform bermudan"
it is a link to pdf files, so they take a bit to download- but i dont know how to give a link to them directly- sorry!! techno -peasant!!
http://www.christinedemerchant.com/sail_sprit_sail.html "

anyway- just want to hear some opinions
many thanks
wayne

[Ixneigh]

This is turning into a cool discussion.
I have sailed on a gaffer, sailed agaisnt a gaffer on my and had extensive experience with smaller lug rigs.

Point. The gaff and the were about equal to weather, but the gaffs clunky, wide, heavy hull fell away in chop. In light air I had to work to pass him. 24 foot vintage center board catboat. In windy conditions he could not keep up with my mac, due mostly to her hull shape and weight. He also has twice the room of the

Point. on my lugrig, there was no noticable difference while on the "weak" tack. While it could point ok, it lost power unless it was windy. I like lugrigs, they are very powerful sails, great for small boats. The sail I had on the v22.2 was amazingly able dispite being pretty small compared to the factory main. About 1/3 less in my estimate.
I would have some derivative of a unicorn lugrig on my if I could find a way to easily unstep a freestanding mast.
thats the killer for me, for gaffs, lugs, junks and like that. The curent rig is pretty damm good, and pretty easy to set up and take down.
I used to think that a gaff would be better for off and down wind on a mac, but last time downwind, I had no problem hitting 7 knots or more, and the sail was all she could handle (defined: let her round up and your out of control) a gaff would make that worse. Give me a good small jib and a main with a proper reduction in it for the conditions, and see you!

point: there are lots of small ocean capable boats. They are all low and heavy. And stout. Very very stout. They wont have standing headroom, or big berths. You wont be able to push the fiberglass in anywhere. They will have a big keel of some sort. They will have a big heavy mast with backstays and intermediates. As boats get bigger, they are allowed to get lighter in relation to length and still be seaworthy.

point: sure thin foils point better on long tacks, but they aren't as handy just kicking around a harbor. A boat with a heavy keel and cutaway will tack on a dime, no problem, and will handle at low speeds, like pinching her up to clear moorings or markers. I almost had some embarrasing moments getting used to my mac coming from keel boats that woukd still steer at nearly a standstill. Those deep thin foils are only good if you are moving fast. Overload that light fast boat and watch how well it points when it cant get up to speed. Take that j24 or whatever, dump 1500 pounds of people and gear on her, then race me in a 26ft folkboat with the same. See you. They are still weight fanatics on those 65 ft sleds.

The only way to improve the basic powersailor concept is to make it a bit larger and use better materials. Ill even leave off the power part, I just want something beachable, roomy, and easy to launch and tow.
make it out of foamcore and epoxy, use the weight savings for more lead ballast.
Ix

[Wayne nicol]

ok... so what do you think of a gaff on the mac, comparable in size to the current main, and then a jib and/or genoa-a gaff cutter!
only reason for the cutter, is to get the balance right with the gaffs c of e being further aft( but also advantageously lower)

[Ixneigh]

A gaff mast needs to be free standing to make maximum use of the sail. At the very least youll need a set of running backs and use them all the time. A gaff main will not allow swept back speaders, and many had no spreaders at all.
in order to fly a jib, you need a tight headstay, hard to do with no or little, masthead support. The runners and maybe intermediates would have to be adjusted every tack, no thanks.
the unicorn lugrig when taken to its obvious evolutionary end, becomes more like a soft wingsail, and has the advantage of an unstayed main, but retains the ability to carry a jib on a very tight headstay. Both the mainmast and the sprit mast are made of carbon fiber and are very light, however I do not think the main mast would be light enough to pull up out of its step by hand. I did have an idea to use the sprit mast and its supporting stays as a method of pulling the mainmast, but I never actually tried it on my old boat. The old boat had a much shorter spritmast then the real deal would have.
Ix

[Wayne nicol]

i would not imagine a gaff 26m with the same size mast- wouldnt need it- would be shorter with no spreaders- about 22', would still have the forestays to run the head sails. having studied other boats that were gaff cutters, or even schooner rigs- i didnt see any with running backstays- well put it this way- the ones i looked at didnt have- and they all seemed to work pretty well.- and they all had side shrouds- none of them were free standing masts.

[J--]

Hmm......my first thought on an alternate rig isn't a gaff.....but a junk/lug rig.

So....a little googling turned up that a carbon fiber mast from a Freedom boat is about $5500 (so it's not a cheap experiment), and I'm not entirely sure how one would step it to a Mac, but the junk is where I'd start.

It's efficient, easy to reef, easy to sail.....ask this guy: http://www.kastenmarine.com/junk_rig.htm

[mastreb]

Sorry it's taking a while for a response.....that whole pesky work thing.....

Well the first half of your post didn't give me anything to disagree with, so I'll save space and not quote it Certainly the Sabre has a lot less leeway than a Mac. At <2 knots, a Mac will make more leeway than headway in a beam wind, leaving the Iron Genny to get you away from the quay if you're not careful.

What neither of us have really talked about yet is the difference between two types of fin keels: Unballasted (where ballast is in the hull) and bulb ballasted. Bulb ballasted fin keels are dramatically superior in pointing ability, even when they're made using the exact same foil dimensions. MacGregor and BWY proved this when they put a 500 lb. lead bulb on the daggerboard of a 26M and--viola--it pointed like a "real" boat suddenly. Why would this matter? Because the dramatic increase in lever arm below the waterline resists heel. If the boat heels less in the same wind, it must necessarily move faster forward, and this assists in increasing apparent wind dramatically, which also increases the ability to point. And none of that increase actually has anything to do with hydrodynamics: It's the same foil profile, and in fact the bulb increases hydrodynamic drag. In fact the leeway should be the same if not greater with the bulb keel, because the sails spill less air over the top.

Weight down low is very important.

You're now saying that the Flicka and Contessa 26 are not offshore capable boats. Um...no. Even if we're sticking just to mono-hulls, and I get that CE certification wasn't really invented till the late 80's but still.....you give me a Flicka and my @ss is outta here!

I'm not going to argue competing opinions that involve differing acceptance of risk, because what you really wind up arguing about is what constitutes an acceptable level of risk. What I'll say is that both the Contessa 26 and Flicka are fine, stout boats, and neither is A-Ocean rated or would qualify to be if they were made today. They would both rate B-Offshore, which is to your point that they're offshore capable passagemakers. A few have made circumnavigations in them, but my point about Joshua Slocum's boat was that you can make a circumnavigation with either luck or seaworthiness, and I prefer not to rely on luck. I'll require an A-Ocean rating for my transits.

Beyond 32 feet, you cannot stay below 10,000 lbs (the towing limit of a consumer truck) without going to extremely exotic materials.

Hmm....I don't know what kind of girly state you live in , but here in the Lone Star State, we can buy trucks that will tow 30,000 lbs. (Ram 3500) and have a total vehicle length (truck and trailer) of 65 feet. So that 39 foot container yacht becomes a "trailerable" boat. You only need a class B license if you go over 26,500 lbs. total. Ok....so, all kidding aside, that's a little extreme, but my point is though trailerable is probably much bigger than you'd think. Easy to launch? Ok. I'll concede 26 is probably the max here.

Back to practicality, what is the point of being a trailerable boat? It's to routinely trailer the boat. If you're merely talking about a transportable boat, then there are plenty of boats that can be transported. If it takes a boat lift to get into and out of the water, then it's not really trailerable. I'm sticking to my guns here at 32 feet, maybe 33 feet maximum. I've seen a Hobie 33 getting into and out of the water, and I've got to say it's a bit awkward. I've also seen a Corsair tri 33 fail to get onto its trailer after two hours of trying and four people maneuvering it in the water, and have to fail back to a boat-lift. I wasn't involved in either of those boats other than to be waiting behind them.

Large roach fully battened mainsails are little more than modern gaff rigs anyway, and they're beginning to dominate the cruising circuit for this exact reason: Better light wind and beam wind performance.

I gotta disagree here again. A roachy main main with battens isn't near the same as a gaff. Battens run horizontally to help the foil shape of the sail and a larger roach in the cut increases sail area. A gaff has the same horrible problem that lateen rigs have: performance on one tack is much better one side than the other because the gaff interferes with the flow of air around the sail. Had you said junk rig, I might have believed you, not a gaff.

Admittedly, the only gaff rigged boat I've ever sailed is an Optimist. But really, if the gaff was a faster, more efficient rig they would be used on Lasers, Hobies, Melges, J's, Colgates, Ensigns, Farrs, 420's, Macgregors, Santana's...etc. But they're not.

Yeah, I'm not really talking about a "classic" gaff rig from 100 years ago on a wooden mast, and I should have been clear about that. The bermudan rig has had 100 years of technological development since 1915, and the gaff rig none. Why? because Bermudas can win races on those triangle courses, and all the development money comes from races.

I strongly believe (and this is my belief, not something I've yet proven) that a modern gaff rig, with aerodynamic spars, will be a more efficient, faster sailing rig on all points except pointing, and even then it won't be much worse than a bermudan. Given the same level of technology, I think they'll be perfectly fine rigs for most purposes.

I'm developing a gaff rig sail with a gaff that rides on a ball bearing car on a mast track (which the sail and boom also ride on) that will allow it to work on a backswept rig without issues, and which will be symmetrical on both tacks. It won't be too long; the mast track is already installed.

I look forward to your reply!

[Wayne nicol]

arent those true junks just a fully battened balanced lug- for all intents and purposes.- although i have seen some newer ones that were more gaffish shape!

my motivation for an alternate rig, is not just for the sake of an alternate rig, but actually to use a shorter mast, so that with mast down, in powering mode, the cockpit is unimpeded.

my first thoughts were with a true sliding gunter rig, not a folding gunter- but rather a sliding gunter, that way i could use the same mast set up- minus the spreaders, mast cut to 19',
3' tabernacle, with baby stays( up to just under boom height, in fact the boom could actually attach to the tabernacle,) and then an 8' sliding gunter spar- with about a 3' overlap( total 11').
the spar goes up with the main, and when you strike the main the spar comes down with it, that way i dont have to make new sails just a small recut on the luff to accommodate the 'step' for the gunter spar.
spar, and collar made from carbon, everything stays the same- would need a new jib and genoa

my second choice is for a gaff rig- just because i love them.
and they DO perform! (has anybody checked out the results of the tests from the link i posted)- with the mac rotating mast and its sail track, with carbon gaff spar, and a good modern cut in modern fabric ...i am very inclined to agree with mastreb- although i think matts rig is steering more towards a gaff/folding gunter type rig( although not a true folding /vertical type gunter) just from what i have understood from him- not absolutely sure- would love to see some drawings.
another great advantage of the gaff type rigs is sufficient sail area- but with a lower c of e- and that can only help a mac!!!!

heck as a group of sailors we already buck the tide- nothing we do is traditional- and we all are pretty much happy with experimentation etc- we're maccers
so this is perfectly in accordance with our general ethos anyway

[Wayne nicol]

sorry J, but i think you might be confusing a sprit with the gaff.
the optimists use a sprit rig, and there is the concern that they have a good tack and a bad tack- although to the average boater the difference is indiscernible.
https://www.google.ca/search?q=optimist ... B400%3B552

here is gaff rigged boat
https://www.google.ca/search?q=image+so ... B460%3B345


here is a junk rigged boat- see how the luff is forward of the mast- yhat will also create a good and a bad tack, unless the sail is swapped every tack
and besides they too are not the best to windward if that was an issue- not for me its not!!- i got an iron genny- if need be.
and their sails are pretty tough to stow down below- if that was ever a required option!
and to achieve the full potential of a junk rig, you need an unstayed mast- and thats a whole 'nuther kettle 'o fish for the mac.

my thing about junk rigs, and this is just personal, is that i think that they should be on a junk and not a western boat- they just look kinda out of place to me. thats just me!!
however having said that i would love to own a true junk one day!!!( boat and rig!!)
https://www.google.ca/search?q=images+o ... B300%3B186

[Wayne nicol]

dont know- but maybe this is the kind of high aspect gaff mastreb is thinking about- not putting words in your mouth mate, just summizing here- please correct me if i am on the wrong tack here
http://www.woodboatbuilder.com/pages/ma ... -page.html

[mastreb]

dont know- but maybe this is the kind of high aspect gaff mastreb is thinking about- not putting words in your mouth mate, just summizing here- please correct me if i am on the wrong tack here
http://www.woodboatbuilder.com/pages/ma ... -page.html

Yes, that's basically it. It would have a sliding gunter, and I'm designing it to work with the current mast and marconi/B&J aft-swept spreaders rig. The core issue is that it moves the CE aft, which should be balanced with a forward staysail on a sprit, although my math shows I can get the CE within 12" of it's current position by furling my genny to 90%. Given that these boats don't have much natural helm leaving the helmsman in a constant fight to keep course anyway, I doubt I'll notice much difference.

[Wayne nicol]

is your gunter going to slide in the track- if so will the track handle the lateral force when under sail.

i did my calculations off the mac drawings off their site- and comparing to measurements against my own sails.

where did you calculate your c of e to be on the original rig, i would like to compare it to mine- in fact i will post a pic tomorrow of my drawings and calcs.