Recent Sailing News:

Artic Expedition
Fri, 4th Sep 2015
Barba will set out on her greatest expedition to date on June 20, 2015, sailing from Stavanger in Southern Norway to the Arctic island of Svalbard and subsequently attempting to circumnavigate the
More..
Spring Delivery Sale on Sails
Tue, 1st Sep 2015
Order between August 31 – September 14, 2015 and save 20% for one sail, 25% for multiple sails Boat must be available to measure no later than September 16, 2015 This is o
More..
Ullman Sails Offshore Cruising
Wed, 19th Aug 2015
Dear Chuck, Kathy, Charlie, and Andrew, I am in American Samoa now, I came here non-stop from San Diego. It was a wonderful shake-down - both for th
More..
CRA Beer Can Races in San Diego Ullman Night
Wed, 3rd Jun 2015
What a great night of sailing.  With great conditions and great competition the  CRA Ullman Sails Beer Can Race with all the Ullman Sails T-Shirts was a lot of fun.  The after party
More..
Whidbey Island Race Week 2015
Wed, 27th May 2015
In 2015, we promise you’ll recognize the great racing in Penn Cove and Saratoga Passage - that never changes. You’ll recognize Charley Rathkopf as the Primary Race Officer and ma
More..

Asymmetric Spinnakers Vs. Symmetrical

What makes them better

Wed, 10th Feb 2010
By Chuck Skewes

Asymmetric Spinnakers Vs. Symmetrical What makes them better
An Asymmetric Spinnaker flown with pole


You may have noticed lately in sailing that a lot more people have asymmetric spinnakers than in the past.  For years some day sailors and cruisers had them because they did not need a pole and it helped with light air reaching.  Not much research went into them because most racing rules outlawed them by limiting the leech lengths of spinnakers or by not allowing one edge to be longer than the other.
This all changed when the Australian 18’ skiffs and International 14’s opened up their rules to allow asymmetric spinnakers.  The results were instant and greatly improved.  These light weight skiffs went close to double the speeds previously reached.  Years later the J80 and Melges 24 were born and then a long line of sport boats all with asymmetric spinnakers.

 

 

 

Still it was not until the late 90’s when heavier keel boats started getting into  asymmetric spinnakers.  With a little rigging work it came possible to fly an asymmetric off a standard pole.  This allowed boats that did not plane to square the pole back and sail deeper. 
Asymmetric spinnakers are much more efficient making them always faster while sailing.  The only time they are slower is while jibing since the sail has to collapse to complete the jibe.  On asymmetric spinnakers the luff is always the luff and the leech is always the leech so it allows us as sailmakers to design the optimum entry and luff curve and the optimum leech exit.  On symmetrical spinnakers the leeches and luff have to switch between each other.  To make this work there has to be a compromise on what is optimal.  It is similar to what it would be like to have a genoa use the leech for the luff on one tack.  This would require a major shape change and would never be as fast.
It is a misconception that asymmetric spinnakers can not sail as low as symmetrical spinnakers.  When put on a pole and squared back they can sail every bit as low and do so more efficiently.  This efficiency turns into speed on the race course.
In the recent Transpac there was only 2 or 3 boats out of the entire fleet that used symmetrical spinnakers.  This is becoming common place in long distance racing as well as around the buoys.
For the cruiser and day sailor there has been a big benefit in the research and development in that the sails are easier to trim and use than ever before.  They are more efficient and this makes sailing easier and more enjoyable as well as widening the wind range that the sail can be used.  The down wind oscillations that use to rock the boats in the bigger wind have almost gone away with the use of asymmetric spinnakers as well. For more information on asymmetric spinnakers contact us at SailsInfo@UllmanSailsSanDiego.com

 

 

 


This article was posted on Wed, 10th Feb 2010