Dimensions Of An Asymmetric Spinnaker

[ggray]

I have specs for an asymmetric spinnaker, I and SPL

What does the I dimension mean? I assume it's the length along the curve of the luff?

What is SPL? By the dimension I have it seems like roughly half the foot.

And shouldn't there be a length for the leach?

[psk125]

I is the height of the halyard sheave from the deck for the JIB.
SPL is the Spinnaker Pole Length. (for symmetrical spinnakers). It is almost always also equal to J : the distance from the front of the mast to the jib tack point.
ISP is the height of the spinnaker halyard sheave from the deck. Sometimes it is the same as I -- if they're at the same height. Sometimes it is higher. Depends on the boat.
TPS is the distance between the tack point of the asymmetrical spinnaker and the front of the mast. If you are flying your asymmetrical spinnaker from the pole, your TPS will be the same as SPL. If your asymmetrical spinnaker will be flown from a sprit or an anchor roller, the TPS will be more than the SPL.
SF is the length of the asymmetrical foot.
SLU is the length of the asymmetrical luff
SLE is the length of the asymmetrical leech
While we're at it, SMG is the asymmetrical spinnaker's mid-girth - telling how deep a sail it is, measured between points half way up the leech and half way up the luff.

[ggray]

Thanks! I'll be sure to remember where this information is!

But makes me wonder about the sailmaker who provided these specs. It's an asymmetric, so why suggest a pole length, and then give no other dimensions? Perhaps he didn't want to disclose his design parameters.