hi just need some advice on adjusting the extension mast to suit new sails.
all i know to do is measure the sail, on the extension mast i have 7 holes to move and adjust... i have a 430 mast.. any help would be great thanks..

Hey Zues, if the windsurfer is from the late 80's, the mast is probably too. Is in fiberglass and in 1 piece? If so there's no point getting a modern sail, as they won't "set" on an old mast - the sort of sail you will need is the type commonly going real cheap on e-bay - if it's got flouro colours it'd probably suit. Check first with local sailors, they might have an old sail in their shed you could get cheap, and try it for size on your mast first. Hope this helps.

Yep, so for that sail (luff 440-445), you need to add 10-15cm of extension to your 430 mast, it looks like the pulley is already set at 12.5, right in the middle of the 10-15 range and should be fine there. Looks like it's a 25cm extension, so you could buy a sail with a luff length of 430 to 455cm, as long as it's similar vintage to the sail shown. Hope this helps