I have several old spinakers but I am a little confused by the sizezing.
My newest purchased from Mr Fowler is a full size Alverbanks.
I have aquired a Speed spinaker that was measured in 1999 that is a little shortet head to foot roughly the same clew to clew but appears fuller towards the head of the sail.
Can anyone explain this tom me i.e. is it a full size one? it is much much bigger than my other spinakers.
Thanks.

There were many differant heights and widths of spinnakers when the rule change came in. The most extreme were the Number Ones with very long leeches designed to be very fast reaching (I thought that idea had it's merits, but obviously noone else did!!).

I therefore wouldn't be suprised to see several utterly differant cuts of spinny from that sort of time.

Well it can't be bigger than 10m2
use the rules to measure it yourself, you will need a calculator

Martin, I had a similar cut spinnaker dated 1998, and it looked very full but overlayed against my "New Rules" one (dated 2006) was clearly quite a bit smaller.

I believe the new rules came in in 2003.

I'm sure you are aware of this, the new rules pole length is 2.3M and anything less makes it very hard to get a good set, regardless of shape.

The previous rule limited the leech length and it wasn't possible to make a sail as big as the present ones in total area that would set well, particularly on a reach.  Actual areas ended up significantly less, but could well have been cut fuller to add area.

standard old sail pre measurement change was about 9m2, new ones 10m2 or less.