Spinnaker Symmetric or Asymmetric

[olliric]

Hello,
I am building a 15 m performance cruising cat and I am in the process of detailing the deck hardware. I am in doubt about the choice of symmetrical cute with the tack on each bow or an asymmetrical run off a 2 m prodder on the cross beam.
The prodder will have a permanent screacher on a furler and at about 50cm up an attachment for another sail.
The prodder will be stayed on each hull just above waterline (10cm). The stay will be wire for the first 75 cm and then on 4:1 blocks. The prodder free end can then be moved to windward when sailing deep with an asymetric with sock on the end.
The alternative will be a symmetrical with braces run off each bow end.
The boat is a fast one and I like to work the boat.
The sailing will be mostly trade wind with the occasional race. While cruising I will probably short handed.
Any idea?
Cheers

[JRMarine]

I'd vote for the a-spin. If your design has any amount of performance, you will benefit from apparent wind angle, which make running the a-spin deeper at a higher speed possible. A sym-spin will only get you going so fast and will only really be usable DDW (Maybe 165 - 195). Both will be equally good in light air. I've built/refit several performance cats and besides requiring a screecher, a good code zero will go a looong way!

[Lancerbye]

If it were a mono I would say asym even though it is not as good DDW as a sym. Having a cat with two very convenient tack/control points I would go sym. The abiity to control a spinnaker without having to use a pole is a treat. I use an asym because I have a mono.

[44'cruisingcat]

If you're going to have a reacher, I'd go with a symmetrical spinnaker. The reacher will still be good for pretty deep true wind angles, and the symmetrical kite will work when you need or want to go even deeper.

To me the function of a reacher and assymetrical kite would overlap too much to be worthwhile.

[HapaPops]

On my trimaran - 34 ft, light, I use both. Higher top speeds with the Assym, but sometimes the VMG (velocity made good ) to leeward is faster with the symmetric.

[Mick C]

May I ask a question?

The terms, reacher, screacher, code zero, asym spin, and sym spin. Are these in the right order from shy to ddw...?

Thanks
Mick

[foolishsailor]

If you are a performance cat you will should be sailing with a significant amount of apparent wind shift and should be focused on vmg sailing versus just wind angle sailing. So you should either get a flat cut spin or sail with an asym. I would sail with a roller furling asym and a roller furling code zero, the roller furling asym will also allow you to sail to higher wind speeds with less crew as you can more reliably roller furl an asym than douse with a sock.

[ggray]

Don't have experience with prodder (I assume same as sprit?) but not having one does not rule out asymmetric.

[olliric]

Originally Posted by jbugbee

I'd vote for the a-spin. If your design has any amount of performance, you will benefit from apparent wind angle, which make running the a-spin deeper at a higher speed possible. A sym-spin will only get you going so fast and will only really be usable DDW (Maybe 165 - 195). Both will be equally good in light air. I've built/refit several performance cats and besides requiring a screecher, a good code zero will go a looong way!

I thought screecher and code 0 are basically the same thing.
My intention is to have a sail on a continuos line furler. This sail, probably a laminate, will have UV protection strip and will always stay on the prodder first attachment. The prodder tip will be for a spinnaker. Given the position it will have to be an asym. spi or a very flat sym. Both could also be tacked on the bows for running. I sailed a sym spi on a reach so maybe a flat sym spi can actually deliver the greatest speed potential and range.

[olliric]

Originally Posted by foolishsailor

If you are a performance cat you will should be sailing with a significant amount of apparent wind shift and should be focused on vmg sailing versus just wind angle sailing. So you should either get a flat cut spin or sail with an asym. I would sail with a roller furling asym and a roller furling code zero, the roller furling asym will also allow you to sail to higher wind speeds with less crew as you can more reliably roller furl an asym than douse with a sock.

Unlike screechers/code 0, due to the nature of the sail material and construction spinnakers are prone to UV damage. I don't like the idea to leave the sail always on and shorten its life. Since it is better to always take the a. sym down, on a cruising boats a sock makes more sense than a furler.

[foolishsailor]

Don't have to leave them up, both can be set Using dynema or spectra stays and halyards and hoisted and tensioned and then furled and stowed below decks when not in use

[olliric]

Originally Posted by HapaPops

On my trimaran - 34 ft, light, I use both. Higher top speeds with the Assym, but sometimes the VMG (velocity made good ) to leeward is faster with the symmetric.

Which is the easiest to jibe. Pull the new sheet over the furled screecher with the assym or the usual swap of guys and sheets with the sym.

[foolishsailor]

Originally Posted by olliric

Which is the easiest to jibe. Pull the new sheet over the furled screecher with the assym or the usual swap of guys and sheets with the sym.

An un polled symmetrical with dual lines to the clews is way easier to jibe as one lime on each clew is a guy and the other is a sheet on each side. To gybe take in the guy on the new side and adjust the sheets accordingly.

If you are using the standard spin with a pole if you have the crew for it in heavy weather is it easier to gybe with a pole as you can let the chute float while moving the pole, in light weather it is easier to gybe with an asym, also depends whether you run the sheets inside or outside the asym as well...The question to ask yourself is will you be flying a chute in heavy weather?

Edit: and it is the easiest to gybe with a roller furling asym. In light weather you can just gybe it, in heavy weather you can furl it and then gybe and UN furl

[olliric]

Originally Posted by Mick C

May I ask a question?

The terms, reacher, screacher, code zero, asym spin, and sym spin. Are these in the right order from shy to ddw...?

Thanks
Mick

Yes that is how I would understand it. However another distinction could be done in two groups along the line of the materials and handling.
One, heavier material with UV protection strips easily furled sail (reacher, screecher, code 0). Good up to close reaching (and more) with any type furler.
two, spinnaker sym and asym.
The second groups would require a sock or a furler with torsion rope for the asym.

[olliric]

Originally Posted by 44'cruisingcat

If you're going to have a reacher, I'd go with a symmetrical spinnaker. The reacher will still be good for pretty deep true wind angles, and the symmetrical kite will work when you need or want to go even deeper.

To me the function of a reacher and assymetrical kite would overlap too much to be worthwhile.

I agree there is quite a bit of overlap.
One problem with the sym spi run off the bows is that may require to take down the screecher furler and lift/remove the prodder. With the prodder out there is the risk of damaging the spinnaker tacked on the bow. That may be a major hassle as I would like to keep the screecher always on and have permanently set countinuous furler line.
If you run the sym off the prodder then you may as well use an assym.