Spinnaker, Gennaker or Pole-out Genua - which is fastest?

[carstenb]

Here's and interesting article from Yachting Monthly where they did a comparision of the three types of sails that can be used when going downwind. Identical boats, sailing in the same wind, each one with a different sail set.

Which is the best way to sail downwind?

This should definitively put this issue to rest

[Jim Cate]

Laid to rest?? I dunno, mate. This test was done in really light airs, and I'm not at all sure that the same conclusions would be reached in, say, 20 knot trades. We don't have a cruising chute, do have a symmetrical kite and do lots of miles with a poled out genoa. The kite, despite being in a sock, is just too much for us in more than ~15 apparent, while the poled out genoa is controllable in twice that, though by that time it will be rolled up to a much smaller sail area.

So, to me this is just another magazine article, published for armchair pilots and wannabees, and nothing definitive at all.

Jim

[carstenb]

Originally Posted by Jim Cate

Laid to rest?? I dunno, mate. This test was done in really light airs, and I'm not at all sure that the same conclusions would be reached in, say, 20 knot trades. We don't have a cruising chute, do have a symmetrical kite and do lots of miles with a poled out genoa. The kite, despite being in a sock, is just too much for us in more than ~15 apparent, while the poled out genoa is controllable in twice that, though by that time it will be rolled up to a much smaller sail area.

So, to me this is just another magazine article, published for armchair pilots and wannabees, and nothing definitive at all.

Jim

Hi Jim,

yep the article is written about light air sailing. Flying a kite or a gennaker in >20 knots is a different animal indeed and probably not something a shorthanded crew (2 persons) will do.

But I think it is interesting to see the results of a side by side comparision in light airs. In strong winds, for short-handed crew this isn't an issue. We'd either fly a poled out genua or simply just the genua alone.

[Snowpetrel]

Interesting. The polled out Genoa did pretty well, 7% slower is no where near as much as I would have expected in light air. If it had been a bigger headsail (rather than what looked like a 100% jib) poled out on an overlength whisker pole with a drifter or cruising code zero type sail to leeward, it would have been even less. Add a bit of sloppy sea to shake the wind out of the baggy spinnakers that would narrow the margin even more.

The racing rules kill poled out headsails by penalizing overlength poles.

Certainly though the kite and asy are quicker to gybe. And a lot of fun, even though they can be hand full at times.

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[carstenb]

Originally Posted by Snowpetrel

Interesting. The polled out Genoa did pretty well, 7% slower is no where near as much as I would have expected in light air. If it had been a bigger headsail (rather than what looked like a 100% jib) poled out on an overlength whisker pole with a drifter or cruising code zero type sail to leeward, it would have been even less. Add a bit of sloppy sea to shake the wind out of the baggy spinnakers that would narrow the margin even more.

The racing rules kill poled out headsails by penalizing overlength poles.

Certainly though the kite and asy are quicker to gybe. And a lot of fun, even though they can be hand full at times.

Sent from my HTC_0PCV2 using Cruisers Sailing Forum mobile app

yeah I was surprised that the poled-out genny did so well also.

[Sandero]

I am with Jim Cate... the spinnakers are for lighter air and finicky and fun and pretty as well. Practical and reefable is the poled out Genny... But that takes a bit of time to rig and so it's sensible for longer passages when you have a down wind sail and more friendly to single and double handing crews.

[brownoarsman]

By their own admission, they didn't try a poled out asy. They also didn't mention a twizzle rig (though I've only tried it twice) which would probably get similar sail area to the spinnaker.

I can definitely relate to the rig-shaking crack of sailing a poled out jib in seas! That was an interesting first experience with that Still not quite sure I've solved it adequately, but got through.


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[bsurvey]

different boats have different sailing characteristics


without a set of polars for the design.


this test is meaningless

[captmikem]

I was coming across the Atlantic with an Alden 54 a number of years back, once down to the latitude of Cape Verde we got the chute up (tri radial) and carried it day and night with an average of 20 to 24 kts of wind.

on the morning of the 12th day the wind quickly gusted up around 30 kts and we broached, vang sheared off, pole broke in two and the chute ripped in two. I carry two poles as it makes Gybing easier, so we set the 130 on the other pole and were underway again. We had been making 180 to 185 days noon to noon, next day our noon to noon was 187, and the following days were much the same.

After that, since there are normally only two of us aboard, we made a rule that we would douse the chute at 20 kts. This has worked well for us through thousands of miles of sailing.

I do not care for ‘crusing chutes’ as any chute needs a pole when downwind, so you may as well have one that is designed for a pole. And that 130 on a pole works great when the wind is over 20, I have carried it (rolled up a bit) with a triple reefed main in 35kts and it just works great as most of the effort is forward and pulling. Boat balances well and it is easy to steer, and easy to get rid of.

Mike

[SVrider44224]

Disagree. Classic design of experiments suggest altering 1 variable.
In this case, condition were the same, boats the same, crew size the same. Only variable was the sail type.



this test is meaningless[/QUOTE]

[canyonbat]

While not a true side by side test, we have experimented a lot using the VMG to wind function on our GPS and found, on our 25 ft Seaward, that our best results are achieved sailing wing and wing using the asymmetrical spinnaker poled out on one side (supported with the spare jib halyard to keep it from collapsing in the lulls) and a jibe preventer rigged on the main. We have sailed this configuration up to about 16 knots of true wind (10 to 11 apparent) which was a bit much. Next time we will douse the chute at about 13 or 14. We were doing about a quarter to half knot better in that configuration than we could get doing deep reaches. There is some gut feel to using this test as the VMG to wind function really jumps around.

Unlike others, I found this article to be useful. I wish I could borrow two more Seaward 25s, equipped just like mine, to do some true comparisons over a few weeks!

[alansmith]

Heh Cars, thanks for the article mate. It does have merit and enjoyed reading it. Same boats, same time, same sea conditions...it measures, imho, what it set out to measure. It's results match what experienced racers know. Bigger the sail area the bigger the boat speed.


What I don't like about Spins is the rolling. Once that begins it is no fun for me. We were club racing on Lake Tahoe on a 27 foot San Juan when the death rolls set in hard. Skipper told me to go forward and get ready to douse the chute. We were veering through the water and surging like crazy...sometimes rails dug so deeply in that it felt like a broach was imminent. I had jeans, tennis shoes, and a windbreaker on. If you fall in the water in Lake Tahoe you have less than 5 minutes survival time. I politely refused and told him it was death on a stick up there. No other crew members would do it either. Somehow we survived the windy patch and we settled back down.


What I would like to see is the same test on like trimarans or cats. Flying a chute is so much easier without poles and wide bases and netting all around for dropping the big buzzards.

[Jim Cate]

Originally Posted by SVrider44224

Disagree. Classic design of experiments suggest altering 1 variable.
In this case, condition were the same, boats the same, crew size the same. Only variable was the sail type.



this test is meaningless

[/QUOTE]

Not so: the sailing techniques were different between the boats, ie, the guys with the assy sailed the angles whilst the others sailed ddw. This immediately gets into apples and oranges. If the gu ys with the regular kite had done the same, they too would have gone much faster... at least, that is so on all the boats I've owned and raced.

Jim

[GrahamHO]

It depends so much on the yacht. Some are faster if they gybe downwind with a gennaker than if they sail square with a spinnaker. Other designs do better flat off individually that is.
Polling out a Genoa is the easiest of all especially if you roll up the headsail, attach the pole and wind the sail back out. With a fairly long pole, about the length of the foot, it can be let forward a bit to go more on a reach. It can be supported with a spinnaker topping lift or spare halyard to a saddle with a ring in the middle of the pole. You do need to have plenty of length in the lazy sheet though.


I think Jim is right that it's just another magazine article. The poor journalist has to come up with stories each month and thinks what the hell can I write about now. They can't write that they haven't any stories this month.

[cwyckham]

Why does it depend on the boat? Polars for your typical cruiser/racer monohull all have the same shape.

In winds over about 20 knots the answer is obvious - Genoa and you'll be DDW once you hit close to hull speed.

In light airs, though, apparent wind is a big deal, as is sail area. Large sail area will win, obviously, but sailing the angles with assym or sym will get you there faster and be more fun.

I haven't used one offshore, but I love the assym in light winds inshore. It's fast, fun, and colourful. I can sail downwind in much lighter winds than I could with a poled out genoa.

One trick I've tried once and loved was a poled out genoa to windward, the assym to leeward and a full main.

The genoa fed the wind into the assym at about 150 degrees apparent. There was just a skiff of wind but we made decent speed and were the prettiest boat in the bay.