Spinnaker

Very often a deck eye screwed to the centre of the pole means the system with a key hole type ring is being used.  A wire keyhole has a fixed length uphaul attached to the top of it and a bungy downhaul attached to the bottom of it.  The deck eye is screwed to the pole in the middle and at right angles to the hooks at the end.  To use it pass the pole through the keyhole and attach the outer pole end to the sheet, the inner pole end to the eye on the mast.  The deck eye stops the key hole at half way along the pole and this braces it at the correct height.  When you want to gybe, release the sheet from the outer end, release the pole from the mast and twist the pole through 90 degrees.  The deck eye now slipes down the pole and when the pole is pushed out on the new side the uphaul and down haul brace it at the correct height.

Wow, a picture is worth a thousand words and this would certainly be the case here.  I'll see if I can find one.  But as a previous poster has said you may find a drawing on another site since this system is also used by many classes such as the 420, 470, Scorpion, Fireball, Wayfarer, Lark and others.  Personally I like the ramp method mentioned above which is very similar in that the uphaul and downhaul are restricted from sliding the length of the pole by something in the middle.

ok sorry these pictures arent very clear, I may resort to drawing a diagram like garry.

and the deck layout. 

Cool glad to have helped, if there is anything else just 'yell'

What club do you sail at? and do you know the name/ no. of the cadet?