PHRF PERSPECTIVE

February 2004

Understanding The New Asymmetric Rule

Racing with Symmetrical and Asymmetrical Spinnakers in PHRF!

Last month we described the new PHRF Class Rule that permits boats to use both Symmetrical and Asymmetrical Spinnakers.  Yet there seems to be some confusion on the issue.  This month, we look at the rule from the standpoint of racing with both kinds of spinnakers and how it helps your performance.

I was able to recruit Bruce Cooper of Ullman Sails (He’s PHRF Big Boat Advisor on the Regional Board) to help us understand the new rule and see how it will benefit all PHRF racers.  Read the text of the rule posted on your PHRF web site at http://www.phrfsocal.org if you like.  Scroll down and use Adobe reader. 

“This new spinnaker rule allows your boat to race with both asymmetric spinnakers (that comply with the new rule) and symmetric spinnakers with NO rating adjustment. This is different from how SoCal PHRF viewed asymmetric spinnakers combined with symmetrical spinnakers in the past.

The rule has restrictions to control size and sail area but ultimately allows for better spinnakers that will be accurately targeted for wind angles and wind strengths.  The new asymmetric spinnakers are very different from both cruising spinnakers and symmetrical spinnakers, which are the most common spinnakers you might see in PHRF racing.  Now you can equip your boat with a spinnaker that will “modernize” your spinnaker inventory with a sail that is used in America’s Cup, Grand Prix and Volvo Around the World racing.

The new rule for asymmetric spinnakers restricts the luff length to a maximum of 103% of the square root of the “I” or “IC” squared plus the “J” or “JC” squared (which ever value is greater).  The luff length was shortened from the previous rule’s maximum length of 115%.  If you prefer, skip the techno- stuff and check with your sail maker-JK.

Maximum luff lengths of 115% are too long and are difficult to fly in light to moderate wind conditions.  These sails were basically built as “rule beaters” to sneak extra sail area into the asymmetric spinnaker while the conventional symmetric spinnaker had a more restricted/smaller size limit.  PHRF has now closed that loophole with the new spinnaker rule and sizes.  We’ve also brought the rule more into compliance with most other PHRF regions and IMS-JK.

So what if your boat is equipped with the old large rule beater size asymmetric spinnakers?  Can you still use them?  The simple answer is YES!  But your boat would be individually rated.  Typical rating adjustment is –6 Seconds per mile.

If an asymmetric spinnaker is standard size in SF, SMG, but more than 103% SL, then it is still considered "oversize" and the boat’s rating will be adjusted for the greater sail area.  If the sail is oversize on the foot and/or mid-girth, then other adjustments will also apply and the rating may change accordingly.

Here’s some options if your asymmetric spinnaker is "oversize” and you do not want any downward rating adjustment:

A. Have the sail(s) re-cut to conform to the 103% formula.

B. Stop using the sail(s) and take them off the boat.

C. Replace the sail(s) with conforming spinnakers.

D.  Apply for a separate Asymmetrical-only Rating Certificate. 

You may NOT fly any symmetrical spinnakers with this certificate.

Whatever you do, you MUST report any additions or changes to the Regional office and your local PHRF Board.  Any change invalidates your certificate until reported and acknowledged.  You’ll get a new certificate with the changes noted.

How often have you watched the sport/pole boats, i.e., Melges and J-Boats sail right through the PHRF fleet where reaching is predominant and just leave everyone in their wake?  Most of the time, right!  Tight reaching while racing is so common in SoCal (i.e. Ensenada, Santa Barbara to King Harbor, Whitney Series, etc.) that the non-sport/pole boats need a way of leveling the playing field.  The new asymmetric sails that SoCal PHRF allows will let you fly a spinnaker that is easier to trim and keep you blasting forward more than tipping your boat over. 

The luff length is a huge factor in how the wind flows across the sail. The longer and tighter the front edge can be, the better the wind flow and flatter shape you can design that will get your boat sailing higher apparent wind angles and sailing in greater wind speeds while reaching before you get over powered.

 However, when the wind goes aft of the beam and the wind angle is a broad-reach to run, it is a whole new game racing against the sport/pole boats.  Your boat is greatly advantaged as you can put up your symmetric spinnaker and trim your spinnaker pole well aft of centerline and go blasting directly down wind on the racecourse!

The new SoCal PHRF rule for spinnakers allows you to race with the symmetric spinnakers you already have in your inventory for wind angles aft of the beam and sail with an asymmetric spinnaker(s) for wind angles on the beam or even forward of it much more efficiently and competitively against boats already using asymmetric spinnakers. In summary, SoCal PHRF racing has joined the 21^st Century of sailboat competition.”  ---Bruce Cooper.

Since most competitive racers replace their spinnakers every couple of years or so, we hope that the addition of an asymmetrical spinnaker would not be too much of a financial burden on the fleet.  When the wind is light, the spinnaker pole usually goes way forward and getting a reaching ‘chute (asymmetrical) would lessen the use of the symmetrical half ounce, giving it a longer life.

If you have any questions about your spinnaker situation, please contact your local PHRF representative or the regional office.  For other information or comments call PHRF at 562-438-6712, see the contact info on the PHRF website or contact us by e-mail: fleetoffice@phrfsocal.org.  Fair winds!

Jerry Kaye

President

So Cal PHRF