Simple question

[Ian McColgin]

I was not aware of any way that compression strain accumulates lower in the mast. The effect of the mast's weight, yes, but that's trivial compared to the compression from the stays.

Many wooden sticks taper from the partners down to the heel as well as from the partners up. The lower taper, unlike the upper, is fairly even. Upper taper is usually minor until the top quarter or higher. Think of it as progressivly lighter topmasts.

Well made spars taper on the sides and front only, leaving a nice straight luff.

The mast takes less strain as it gets near the top - less force from the sailarea pulling it aside. Remember that the jib and stay are really compression. So the good reason for taper is to lighten the boat aloft. Most aluminum masts just don't lighten enough to justify the expense on that ground but aesthetics mater as well.

Unstayed masts are often tapered, whether wood, aluminum or graphite, to provide some air power controled bend.

G'luck

Ian