Windsurfing mast foot

Question
Hello, I found your website during a search for a O'Brien Mast Foot. Like a lot of people I found an old O'Brien set up for free.  I always wand to try wind surfing and thought this was a good opportunity.  I have read a lot of your replys on the O'Brien mast foot being obsolete (mine is missing), and I have figure out how I want to attach a newer style 2-bolt base with the rubber hourglass shape.  My question is; what is the inside diameter of a common mast?  The mast I have is about 1-15/16 or 50mm inside diameter at the base.  I have looked at the details and specs on the websites that sell mast bases / foot, but I have not found a diameter listed for the mast size they fit.
If my mast (one piece fiberglass) is unique in diameter is there a way to adapt the above mentioned base?
I guess to sum it up, I was wondering if a modern style base will fit into my mast right out of the box, or if I need an adapter of some sort.
I also should mention that I have no pulleys at the mast base, I would like to find a base with them built-in, but if an extension with them is the only way I understand, but then the diameter of the extension would be the important diameter I need.
The closet windsurf shop is about 4 hours away.
Yes I know the board was free for a reason, but if I spend a few bucks and get it working and like it, then the base / extension will be useful on a newer board, with little start-up costs.

Any help would be great.

Answer
Hey Daniel,

There are only two sizes of mast diameter and yours would be considered a standard size mast. The other is called 'skinny' or RDM (reduced diameter mast). The RDM masts are all aftermarket and are used by choice usually by advanced sailors.

Your standard mast will fit any standard mast base. Most new bases are designed to use with an extension. The extension is the part that will have the pulleys built in. They are different lengths and designed to adapt different size sails to the same mast.

If your mast track works for a two bolt base, a single bolt base will work just as well. If your track is a slot that the base nut (or slider nut) goes into and then the base then threads into the nut and tightens the base to the board, then a single or two bolt base will work. The track is long to accomodate different positions on the board for different wind conditions. More forward for light winds, back for higher winds.

Check out chinooksailing.com for bases and extensions. Also check out windsurfingmag.com under links for various shops that you can order bases online.

Hope this helps.
Keep on sailing,
Windlover