This makes much more sense, I also have a standard mardi gras sail and both a polar radial and polar laser 2, I just have seen those more often and the Horizon was unknown to me. Thanks for the help!I am afraid that I don't think this is a "rare" sail as such.
Back in the late 70s and through the 80s there were a number of coloured sails made for the Laser (which were all class legal). This model was known as the "Horizon"
Indeed, coloured sails were provided with the boats at the 79, 80, 82 and 83 Laser Worlds (no Worlds were held in 81).
As for the sail number on your sail, I have no information on that. It is not impossible that a previous owner did own Laser #692 and subsequently purchase this coloured sail for it. But we will probably never know unless you are able to research it further through the seller you acquired the sail from.
But I don't think it would have come from an event as such, if that is what you meant.
If you go to this thread here, you will see copies of brochures which include the Horizon sail, and many more and the coloured sails used at those Worlds mentioned above:
If you are interested in special edition lasers, then this thread has lots more, as well
Doing my usual thing and looking at the usual for sale boards I have noticed quite a few 'special addition' Lasers about. the Black Magic, Race '99, Ben Ainsle, Graffiti how many different special addition Lasers are there and are there specific sail number bands which they cover, are they...sailingforums.com