I was sailing an ARC 22 today with four people aboard in 12 - 17 mph true wind speed. Going upwind with two on trapeze, one hiked, and one on the leeward hull the mast started pumping from app. 6" bend (part prebend, part downhaul) to at least that much in reverse bend (probably much more - it looked scarily wrongly bent when first noticed. Immediately depowered (sheeted out and came in off trapeze). Applied max downhaul to force mast to stay in proper bend (prevent bending backwards in the middle) and that helped but did not keep it from bending back again as power was applied. The spreaders are not adjustable. The owner has already broken a mast when sailing with three up and now I know why.

I am seeking comment from anyone who knows about ARC 22s breaking masts and/or with similar experiences. Especially interested in fixes. We will be contacting Tom Haberman but would first like to survey for similar experiences.

Thanks in advance for useful, on topic, comments.