Spinnaker dimensions

[Brad Costan]

Does anyone have the dimensions for a class legal tri-radial spinnaker ?

thanks
Brad

[Bill Sedgwick]

Brad,

There are 2 parts to this answer: 1) C34 national class rules and 2)PHRF-SD rules.

C34 class rules prohibits assymetricals and is as follows (http://www.c34.org/rules.html):

4.11.4 SPINNAKER
4.11.4.1 The host fleet may specify or prohibit use of spinnakers.
4.11.4.2 When permitted, the spinnaker shall be a three-cornered sail symmetrical about its
centerline with a maximum girth of 24 feet 4 inches. A handicap may be specified
by the host fleet based on performance data.

San Diego PHRF
(http://www.phrfsandiego.org/PHRFSD2004/ASails2004.htm)is basically the same as PHRF SoCal and states the following:

SAILS Headsail LP shall not exceed 1.55 x J
Symmetrical Spinnaker SL shall not exceed .95 times the square root of (I² + J²)
Symmetrical Spinnaker SMW shall not exceed 1.8 x J
Asymmetrical Spinnaker SLU shall not exceed 1.03 (the 1.15 is only for boats designed for asymmetrical chutes) times the square root of (Ic² + Jc²)
Asymmetrical Spinnaker SF shall not exceed 1.8 x Jc
Asymmetrical Spinnaker ASMG shall not exceed 1.8 x Jc
Asymmetrical Spinnaker ASMG/SF ratio shall be equal to or greater than 0.75
POLES Spinnaker pole shall not exceed 100% of J. The parameters for Spinnaker Pole measurement are the same as SPL (Appendex A, Section 1.0).
Extended “bow pole” (BPL) shall not exceed original manufacturer’s designed length.
Whisker pole maximum length shall not exceed 1.4 x J.
Boats racing in a designated Non-Spinnaker race may use a whisker pole. Adjustable length whisker poles shall have a 2-inch contrasting band indicating maximum allowable length. When in normal use, these poles shall not be extended beyond their maximum allowable length, and shall be attached to any point on the mast.

In summary:

If you have a standard rig C34 then the I = 44, J = 13.5 and SL = 43.72(max)and SMW = 24.3(max)

You can carry both a symetrical and a assymetical in SoCal but the asso must be measured using the Jc dimensions and must be on the certificate. In addition, make the SMW 24.3 to be safe.

I'm on the PHRF San Diego board so if I can help, feel free to contact me. Hope this helps.

George Sedgwick
SGYC Measurer