As my second given name is precision, how to get the round supports for the partners?

Anonymous wrote:

That pain will soon be all forgotten :-D

First cut is the deepest...

You can make an internal sleeve from the same size tube with a sliver cut out from it - I had one inside Tystie's mast - but it's hard to do, and I'm not convinced it adds much strength. I think it's better practice to use a sleeve of uncut tube, and if it's too big, fill the gap with casting polyurethane.

Yes, the maximum bending stress is at deck level.

I can think of two 8 metre boats with 6" x 3/16" masts - Fantail and Fanshi. However, these masts are hybrids, and the tube portion is of a stronger spec than the usual 6063 of a spun-tapered flagpole. I think the spun-tapered tubes will be stiff enough; and will be strong enough for cruising in a fairly relaxed manner. For cruising to wild and remote areas, perhaps the lower end could be reinforced by an external alloy sleeve extending from the heel up to the tack area of the sail, if one can be found that is a reasonably close sliding fit.