W-brackets are a workable Atlas mounting solution for a variety of masts.  Unlike boat-specific brackets that fit each mast profile exactly, W-brackets touch masts at three points—on the leading edge and on each side.

Two sizes are available—a small, which fits many dinghies; and a medium which fits many cruisers.  See diagram showing dimensions of both, to determine which would be best for you.  Harken non-skid strips are provided to customize your fit. Also, a safety tether and fast clip.