# Flying an undeclared oversized jib as a spinnaker



## mikehoyt (Nov 27, 2000)

I have been asked if a boat that has declared a 150 as largest genoa with a standard spinnaker can use an undeclared sail (170 genoa) not as a genoa but flown as a spinnaker.

the words were "flying my 170 but like a spinnaker, with the Tack poled out to windward on the spinnaker pole and of course not hanked on".

Does a boat that does this with a sail that has the hanks on the sail but not attached have to declare this as an oversized headsail? Even if not ever intending to use as a genoa in a race?
Is this legal to fly as a spinnaker given the construction of the luff ona typical 170 genoa?

Are there other considerations?

Thanks

Mike


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## dpboatnut (Jun 22, 2002)

There are different definitions for headsails and spinnakers. Generally, the mid-girth (the distance between the half-leach to the half-luff) needs to be less than half the foot or LP dimension, ensuring straight or concave leading and trailing edges. A spinnaker needs to have its mid girth at least 75% of the foot dimension, ensuring that at least one of the vertical edges will be very convex, or roached. The sail''s attachment (or not) to the stay is usually not relevant.


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## sailingfool (Apr 17, 2000)

Here''s the rule for spinnaker size, you can figure out whether a 170% would fit the measurements:
"a spinnaker width equal to 1.8 times J, a spinnaker height equal to .95 times the square root of I squared plus J squared"

If somehow this fits within the rules, it leaves open the question of why in hell would you do this as the perfomance would probably be horrendous, if the sail even fills...??


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## mikehoyt (Nov 27, 2000)

This was a question posed by one of our club members who had read about it in a book. He states it used to be a practice sometimes used when the winds were too high for the normal spinnaker.

I think that today anyone wanting to run a spinnaker in a high wind would have a sail built for that purpose so this 170 business would not be done. I was just looking for some answers to a rather interesting question.

Our local PHRF association handicapper has stated that it would be viewed as a headsail since at the midpoint its girth is less than half of that normally assigned to a spinnker so that by definition it is a jib. He further went on to say that if on board in our association it would be considered inventory and the boat would be penalized 6 secs per mile for an oversized jib.

Mike


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## TSOJOURNER (Dec 16, 1999)

Sailingfool,

Actually, that is a valid way to fly a headsail when going downwind. Its much more efficient than poling out the clew as when going wing & wing because the luff of the sail remains the leading edge and is out of the turbulent air from the main. When the clew is poled out (wing & wing), the leech is the leading edge and this is just plain backwards.
Poling out the tack is an efficient and stable manner in which to go downwind in heavy air if the spinnaker is too much but main alone is not enough or too rolly. It would be faster than no spinnaker at all and maybe easier to manage than a small spinnaker.
The ''modern'' spinnaker actually evolved from this practice.
Try it sometime, you''ll be amazed.

As to the legality of it in a race....I guess it would depend on whether the committee based their definition of sail type on dimensions or implementation. I would tend to think it would still be classed as a 170 Genoa and penalized as such because there''s nothing to prevent it from being used as one, despite claimed intentions to the contrary.

AJS


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