Code Zero TWA

JRT

.
Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
While I really want a full set of new sails, the reality is I have a lot of improvements to work on. I do think after our first season with the 310 I really need a lite air sail. The recommendations so far are code zero or cruising spin. The code zero says can be used up to 45 deg TWA, cruise spins is up to 90 deg. I don't spend much time running downwind but do seem to need to go upwind on very low wind days more.

So question, is 45 deg TWA realistic? Is Code zero a good first spin type sail? I had a drifter on my O'Day 25 that was hank on and was just wonderful to fly on the low wind days we get here and I miss that capability now with the 310.
 
Jan 2, 2017
765
O'Day & Islander 322 & 37 Scottsdale, AZ & Owls Head, ME
A code 0 is extremely versatile and great is light winds. It can be flown from 40 to 140 AW. Aysemetric spin best 90 to 180 AW. But you’ll need a bowsprit to fly either properly. I recommend Selden retractable.
 
  • Like
Likes: JRT
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
After our second season with our new Code Zero, we couldn't be happier! Our first boat was much lighter, with a much larger headsail. What we missed most, after moving to a larger boat, was the light wind performance. It was incredibly frustrating to have to motor in conditions where we would have been perfectly happy on our smaller boat. The Code Zero put the light air fun back into our SAILING. One of the best sailing days ever for us was, an 8 knot (TWV), 19 NM close reach, with our new Code Zero. :thumbup:

Can you tell that I like it? (Edit: Should say "we" like it!)

Slides-020.jpg
 
Last edited:

AaronD

.
Aug 10, 2014
723
Catalina 22 9874 Newberg, OR / Olympia, WA
:plus: on @SoSound's comments. We don't get 45-degree TWA - probably closer to 60-70 (that could be the cut of our particular C0, or - more likely - the skill of the skipper involved). But we love sailing in light air when we might otherwise be motoring. Details on ours (for a much smaller boat than yours) at Sailing and restoring #9874 and the next page or so of posts on that thread.
 
Last edited:
Oct 22, 2014
20,993
CAL 35 Cruiser #21 moored EVERETT WA
@SoSound You certainly got a Cheshire Cat like grin going.:biggrin:

You are aware, we know, you are sailing in the PacificNW. And sometimes, not saying this time, locals break out in odd looking face grimaces (kind of like smiling) when they feel the sun on their faces.:yikes::what::redface:

You look like the sun is on your face and you are looking up into it...


Thanks for the followup on the sail experience. There was a lot of consideration that went into that acquisition. It is great when it works out.
 
  • Like
Likes: SoSound
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
While I really want a full set of new sails, the reality is I have a lot of improvements to work on. I do think after our first season with the 310 I really need a lite air sail. The recommendations so far are code zero or cruising spin. The code zero says can be used up to 45 deg TWA, cruise spins is up to 90 deg. I don't spend much time running downwind but do seem to need to go upwind on very low wind days more.

So question, is 45 deg TWA realistic? Is Code zero a good first spin type sail? I had a drifter on my O'Day 25 that was hank on and was just wonderful to fly on the low wind days we get here and I miss that capability now with the 310.
Expecting to sail at 45 degrees TWA for a Code Zero is not realistic. That's how high a cruiser can point with a tightly sheeted. optimally designed jib or genoa. With a genoa and enough power and boat speed, 45 TWA corresponds to around 30 degrees apparent wind angle. That's good performance for a cruising boat using a genoa or jib to get upwind.

What really matters, though, is VMG upwind (velocity made good), not TWA. If you are sailing really slowly at 45 TWA, your progress to your upwind destination is slow. If your boat speed is really fast at 55 TWA, you'll get there before the other guys who are pointing higher but at lower speeds.

Different rigs use different shaped and sized Cruising Code Zeros. If your Catalina 310 has an overlapping genoa (approx 125%-ish), the code zero will generally be about 1.5 times the size of the genoa. It will not point as high as a genoa, but it will make the boat sail fast on a close reach.

For example, let's say your code zero will only point as high as 55* degrees TWA. How fast do you need to sail to get upwind faster than using your genoa with a 45 TWA? Here's the answer: if you can get the boat going about 25% faster at 55* using the code zero rather than the genoa, you will get to your upwind destination sooner. than you would using the genoa at 45* TWA.

So, if you can make a code zero that is big enough and powerful enough to really move the boat faster in light winds, you'll be fast. It' really IS all about VMG, not TWA.

Cheers,
Judy

PS. BTW, we can design custom design cruising code zeros differently for boats with non-overlapping headsails than for those with overlapping headsails. For the former, we make them smaller and flatter and design them to fly as close as AWA of approx 30-35, because the jib is frequently inadequate. For the latter, we make them bigger and fuller and they can fly at slightly lower angles, because the genoa is adequate for pointing high in medium breezes. It's always a design trade off between powerful (big and deep camber) vs pointing (smaller and shallower camber).

For race sails, the sail designer has more constraints due to racing rules.
 
Last edited:

JRT

.
Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
Thank you soo much @DrJudyB ! I was really looking for that feedback to understand my expectations.
 
Sep 11, 2015
147
Hunter 31 Marina del Rey
A code 0 is extremely versatile and great is light winds. It can be flown from 40 to 140 AW. Aysemetric spin best 90 to 180 AW. But you’ll need a bowsprit to fly either properly. I recommend Selden retractable.
I do not fully understand the rationale for a code 0 given the above but I have little experience with downwind sails. If a code 0 is flown between 40 and 140 AWA, what is the benefit compared to a 155% genoa that can be flown between 30 and 130 AWA, works with greater wind ranges (10-25 knots) and can be easily reefed in bad weather? Is the material lighter, so that it is more efficient in light winds (5-10 knots)?

I agree that an asymmetric can be flown from 90 AWA to close to dead downwind but typically, it is a different cloth for different wind speeds. You need a large asymmetric to give you decent speeds at say, 10-12 knots true wind speed/170 AWA. The same sail will overwhelm most boats/captains at 15 knots/90 AWA. May be I am exaggerating a bit but it seems to me that downwind sails have very specific wind speed/AWA sweetspots.

SV Pizzazz
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
I do not fully understand the rationale for a code 0.... If a code 0 is flown between 40 and 140 AWA, what is the benefit compared to a 155% genoa that can be flown between 30 and 130 AWA
On our boat, the Code 0 IS the 155% (or greater) genoa in light wind. On our boat, with outboard shrouds, our regular genoa is only 106%.

The Code 0 is on a furler, which makes it much easier to handle shorthanded than the asym in a sock. The possibility of sailing it upwind at all means that we will, and do, use it much more frequently. If the wind picks up, we can furl the Code 0 and switch to the genoa. With the Code 0 on a furler, we can leave it up for a period of time and choose to use it, or not, as conditions dictate.

If we had a large overlapping genoa, as we did on our first boat, we might not have the code 0 now. But for us, using a code 0 on a furler has meant more time under sail after upgrading to a larger boat, which is double the displacement, with only a small relative increase in the size of our genoa.
 
  • Like
Likes: JRT
Jan 2, 2017
765
O'Day & Islander 322 & 37 Scottsdale, AZ & Owls Head, ME
. If a code 0 is flown between 40 and 140 AWA, what is the benefit compared to a 155% genoa?
SV Pizzazz
A Code 0 is made of lightweight nylon vs a Genoa’s heavier weight Dacron, and is larger than even a 155 Genoa. It is therefore a much better light wind sail. I furl it when wind speed hits 15 knots and unfurl the Genoa.
 
  • Like
Likes: JRT
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
I do not fully understand the rationale for a code 0 given the above but I have little experience with downwind sails. If a code 0 is flown between 40 and 140 AWA, what is the benefit compared to a 155% genoa that can be flown between 30 and 130 AWA, works with greater wind ranges (10-25 knots) and can be easily reefed in bad weather? Is the material lighter, so that it is more efficient in light winds (5-10 knots)?

I agree that an asymmetric can be flown from 90 AWA to close to dead downwind but typically, it is a different cloth for different wind speeds. You need a large asymmetric to give you decent speeds at say, 10-12 knots true wind speed/170 AWA. The same sail will overwhelm most boats/captains at 15 knots/90 AWA. May be I am exaggerating a bit but it seems to me that downwind sails have very specific wind speed/AWA sweetspots.

SV Pizzazz
You have to realize that Code 0s were designed originally for boats with non-overlapping sail-plans, and those are the boats that derived the greatest benefit. These boats go upwind just as well as overlapping boats, but as soon as the wind starts to move aft and the apparent wind speed starts to drop, they start to loose out. A code sail fills the gap between jib reaching and a deeper running spinnaker.

You can use code sails on genoa driven boats, but the applications are narrower. This is becase a large genoa has a wider application when off the wind.

And yes downwind sails are targets. We use something like this.

260 spin wind chart.jpg
 
  • Like
Likes: JRT
Sep 11, 2015
147
Hunter 31 Marina del Rey
Thank you, it is very helpful to understand the evolution of the sail plans and the reasons all these sails were developed. I am not trying to steal the thread but it could be helpful to all of us if someone could give a historical perspective on sail plans. The way I understand it is:

Boats from the eighties had a mast head rig, multiple jibs/genoa's and relatively small mains. They would typically use spinnakers for downwind sailing. The 155% genoa was/is a versatile sail for those rigs. Then people realized one sail weight is not enough for all wind speeds/angles, so they moved the rig forward, making it a fractional rig with smaller jibs. The jib became an upwind sail only and most of the drive was coming from the main. Spinnakers went out of favor because they are too much work. Instead of having one heavy genoa, now you have a small jib for upwind work and an asymmetric for broad reaching. Then people realized that if you have a flatter stern and sufficient power you develop more speed and better VMG downwind when broad reaching, so now you have a number of asymmetric/code 0 whatever sails that maximize the broad reaching speed. Is this approximately correct?

The question then is, if I have an eighties boat (Hunter 31) and my downwind performance is lacking, what is best for me? Get a spinnaker and learn how to manage it single handed or get an asymmetric and gybe downwind? Not only in terms of speed but also in terms of handling, cost to install (i.e. polling out the genoa is easy, while having a spinnaker pole is a lot of cost and effort, rigging, etc.). An asymmetric would be an easy addition (just a hallyard, possibly a sprit) but will it give me good VMG downwind given that my stern was probably not designed for an asymmetric? Ideally, I would like to compare polars of similar boats to my Hunter 31 for polled out 155% genoa, asymmetric and symmetric?

Thank you,
SV Pizzazz
 
  • Like
Likes: SoSound
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Thank you, it is very helpful to understand the evolution of the sail plans and the reasons all these sails were developed. I am not trying to steal the thread but it could be helpful to all of us if someone could give a historical perspective on sail plans. The way I understand it is:

Boats from the eighties had a mast head rig, multiple jibs/genoa's and relatively small mains. They would typically use spinnakers for downwind sailing. The 155% genoa was/is a versatile sail for those rigs. Then people realized one sail weight is not enough for all wind speeds/angles, so they moved the rig forward, making it a fractional rig with smaller jibs. The jib became an upwind sail only and most of the drive was coming from the main. Spinnakers went out of favor because they are too much work. Instead of having one heavy genoa, now you have a small jib for upwind work and an asymmetric for broad reaching. Then people realized that if you have a flatter stern and sufficient power you develop more speed and better VMG downwind when broad reaching, so now you have a number of asymmetric/code 0 whatever sails that maximize the broad reaching speed. Is this approximately correct?

The question then is, if I have an eighties boat (Hunter 31) and my downwind performance is lacking, what is best for me? Get a spinnaker and learn how to manage it single handed or get an asymmetric and gybe downwind? Not only in terms of speed but also in terms of handling, cost to install (i.e. polling out the genoa is easy, while having a spinnaker pole is a lot of cost and effort, rigging, etc.). An asymmetric would be an easy addition (just a hallyard, possibly a sprit) but will it give me good VMG downwind given that my stern was probably not designed for an asymmetric? Ideally, I would like to compare polars of similar boats to my Hunter 31 for polled out 155% genoa, asymmetric and symmetric?

Thank you,
SV Pizzazz
To fully understand this you have to look at sailplan performance, and yachting rules over time. They drive yacht racing design, and therefore yachting 'fashion', and cruising yacht design.

Back in the 50s starting with the CCA rating then the IOR and even continuing to PHRF, racers and designers were faced with a rule that rated sail (AKA boat horsepower) area as .5(J*I)+.5(P*E), NO MATTER HOW BIG YOUR GENOA**. So what did this do? You got boats with tiny mains on short masts, and huge overlapping (up to 180%) genoas. It was 'free' horsepower. This flew in the face of what designers knew would actually give best real-world performance (high aspect rig) but the rules won out. Race boats got designed like this, and cruisers followed along. For decades.

Once IOR gave way to the non type-forming IMS rule, tall non-overlapping rigs started to take over. Everywhere except for USA-serving builders, where racing under PHRF (which allowed up to 155% without penalty) continued to rule. Interim boats from around 2000, like the First 36.7 and the J/109 raced with genoas here in the US, but with jibs in Europe. But make no mistake, a overlapping raceboat has not been designed in 20 years. This has finally been helped along in the USA where finally most PHRF boards now give credit for smaller than 155% headsails.

Cruisers soon learned the advantages of non-overlapping rigs. The smaller single jib could be used in 90% of wind conditions. And the bigger main still just dropped into lazy jacks. But the weak spot is off-the-wind. On BlueJ as soon as we crack off we're looking for a kite. The current joke is 'race boats used to carry 4 headsails. Now they carry 1, but 4 spinnakers'. And that's true for us!

But what about the cruisers? Spins and codes will help, but it's work/trouble/hassle/etc. Well, thank the French. Their crazy desire for short handed/solo racing created a similar need, an easy-to-deploy spinnaker system. That's where endless line furlers were invented, and the tech trickled down to cruisers.

Now it's not uncommon to see non-overlapping cruising boats with a furler kite set on the bow, ready to deploy as soon as the wind moves far enough aft. And when cruising, if the wind is not quite far enough aft, turn down! ;^)

** ever wonder where the term 'rated sail area' comes from?? Now you know.
 
Last edited:
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
The question then is, if I have an eighties boat (Hunter 31) and my downwind performance is lacking, what is best for me? Get a spinnaker and learn how to manage it single handed or get an asymmetric and gybe downwind? Not only in terms of speed but also in terms of handling, cost to install (i.e. polling out the genoa is easy, while having a spinnaker pole is a lot of cost and effort, rigging, etc.). An asymmetric would be an easy addition (just a hallyard, possibly a sprit) but will it give me good VMG downwind given that my stern was probably not designed for an asymmetric? Ideally, I would like to compare polars of similar boats to my Hunter 31 for polled out 155% genoa, asymmetric and symmetric?

Thank you,
SV Pizzazz
In almost every case, I would suggest an asym. The cost and ease rule. The ONLY true exception would be if you were MUCH more concerned about VMG than speed. Most cruisers just want the boat to move well, and let the VMG take care of itself. And it will, except for W/L racing, and sailing in the trades. W/L racing? Get a sym kite and a pole. DDW in 20 knot trades? Poll out your 150%.

PS - There is nothing wrong with your mainsail pressed against your spreaders. Just get good spreader patches.
 
  • Like
Likes: Grotto
Sep 11, 2015
147
Hunter 31 Marina del Rey
Thank you, it all makes more sense now. I am quite happy with just polling my genoa in light winds and above 15 knots I make close to hull speed anyway. The only problem is that I lose poles approximately once a year but that is just being clumsy. So, for a trip Marina del Rey to Hawaii, cruising, should I get an asymmetric or just a spare pole? I estimate it would make a difference of 1-2 days max. in terms of the total journey time.
 
Sep 11, 2015
147
Hunter 31 Marina del Rey
The current joke is 'race boats used to carry 4 headsails. Now they carry 1, but 4 spinnakers'. And that's true for us!
I think that is the core trade-off for cruisers. I carry a 155% and a 110% genoa's for my boat, so I have only one sail to store. It is not that much work changing the sails over, although taking the 155% off the furler in a breeze is messy on the deck. Still, it is only one extra sail to store. Now, if I get 1-2 spinnakers + the lines and the spare main and there will be no space on the boat for myself. Ideally, I should get an asymmetric on a second furler on a bowsprit as you suggest but this is something like a $4-5,000 expense comparable to a new engine :).
 

JRT

.
Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
This is great info and help! I'm 99% of the time looking to just move around the lake on our limited days we can and it seems low wind days are not great with the 135 jib and main. I also noted in our river race a few weeks ago the only boats I think that managed to finish a lap in the time limit had spins / code 0 / drifters.

Cost wise this seems like a no brainer to me, a code 0 on my boat in 1.5 oz single color is under $1700 from Precision with their black Friday discount. I know it doesn't fix all points of sail but should help fill in some with the wind conditions we have. The Hunter 31 is pretty similar to the Cataline 310 looking at sailboat Data info so I would guess a similar price.
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
I think that is the core trade-off for cruisers. I carry a 155% and a 110% genoa's for my boat, so I have only one sail to store. It is not that much work changing the sails over, although taking the 155% off the furler in a breeze is messy on the deck. Still, it is only one extra sail to store. Now, if I get 1-2 spinnakers + the lines and the spare main and there will be no space on the boat for myself. Ideally, I should get an asymmetric on a second furler on a bowsprit as you suggest but this is something like a $4-5,000 expense comparable to a new engine :).
A Code 0 can be a very versatile sail. Just talk to your sailmaker about your intent. The biggest diff between a zero and AP asym is that the zero will not rotate in front of the boat like an asym will. This limits running capability. But in most conditions its better then a headsail, just not optimal.
 
  • Like
Likes: JRT