Asymetrical spinnakers

[Irwin32]

What are the following measurements on an Asymetrical spinnaker for PHRF?
SLU, SLE, SMG, SF

[sailorbandido]

SLU is the Spinnaker Luff
SLE is the Spinnaker Leech
SMG is the Spinnaker Maximum Girth
SF is the Spinnaker foot

The area of an assymetric spinnaker is given by the formula:

Area=(SLU+SLE)x((SF/12)+(SMG/3))

[JIO]

I own a 30''cruising boat that has a fractional rig. Someone just gave me an asymetrical spinnaker/gennaker, that would be flown without a pole. I have never used such a sail (or a conventional spinnaker for that matter) nor have I ever sailed on a boat that had one. Just a few basic questions: First, can you tack with these sails? If so, is it a problem getting the sail around the forestay? Second, although I have a fractional rig, I have a third halyard from the top of my mast. Do you think I can fly this sail this way notwithstanding the fractional rig? I guess if tacking with this sail is an option, I could not do this with this setup??? Thanks for the advice.

[Jeff_H]

I guess the first question that I would ask relates to the size of the assymetrical chute that you were given. On most older fractional rigs, the spinnaker halyard exits the mast just above the forestay or at the forestay.Is the luff of the new spinnaker roughly a couple feet shorter than the length from your anchor roller to the spinnaker halyard exit block. If so that would be the halyard to fly the chute from. You can''t tack an assymetrical spinnacker but you can jibe them. Normally on a cruising boat without a sprit the chute is jibed around the outside of itself. That means that you have two very long sheets and let the active sheet run until the sail is beginning to flag in front of the boat and then bring it in on the other side.

Without knowing the type of boat it is hard to say whether you can fly the chute from the masthead or not but generally frac''s do not have the lateral strength at the masthead to fly an assymetical chute without adding cap stays to take the side loads. On the other hand a chute that big may be too much for the boat to handle in anything but very light winds.

Jeff