Hi Albert
If you want to put your email in your profile I will send you pics of the and sizes of the one I built for my Hummingbird 30.
Cheers, Eamonn.
Take your dimensions from the boat.
You will need the shores to ideally coincide with bulkheads, therefore a distance between main bulkhead and the partial bulkheads at or somewhere below the forward end of the cockpit will give you your length whilst width of cradle should ideally be the full beam of the boat with shores adjusted in to approx 1' less than the waterline beam at the two bulkheads.
You can use your draft to estimate the adjustable length of the shores, not forgetting that the boat will probably be stand on blocks. Good luck.
I've got a Moody 31 fin keel and a cradle from Joseph's in Ipswich that I bought with the boat. Adjustable for length and the spread and height of the uprights. If you send me your email I'll measure and send you details with pics after I've been out there on Thursday.
Alternatively you could creep into a boatyard and measure up from a similar boat.
There is one on eBay at the moment - no picture and he is a newbie with zero feedback so you'll have to email him for more info. Probably cheaper and less hassle than making one!
See:- http://cgi.ebay.co.uk/Yacht-cradle-suit-...1QQcmdZViewItem
Make sure you ask all the questions - who made it? How old? what boat did you have in it? is it fully adjustable? etc etc