Alternative Rigs for Multihulls

I’ve posted some brief notes about multihull rigs on the “Useful Articles” pages of my website, www.sailingcatamarans. com. There, in the “Different Design Features” section, I explain why the sensible choice for multihulls is the single-mast Bermudian rig, either masthead or fractional rig.

- Richard Woods

Many people, however, want to experiment with alternative rigs so I thought these even briefer notes might help separate fact from romantic appeal.

Most alternative rigs are based on those used on various working boats in use around the world. However one must remember that, unlike recreational craft, which need to be good all-rounders, working boats didn’t just sail, they fished, or traded. The actual voyage was just a means to an end.

The traditionally shaped gaff rig was often used by fishermen as it was easy to “scandalize” when dredging or trawling. It is still used today on the Falmouth working boats for that reason (they have to dredge for oysters under sail, since engines are not allowed).

The Dutch trading boats used a short gaff and that is much more efficient, creating a simple “sawn-off ellipse” shape. The resulting sail is similar to the modern square-top mainsails you seen on race boats and many multihulls.

The problem is that the gaffis much heavier than a batten. And the weight is in completely the wrong place so stability is reduced and pitching increases. The other problem is that to allow the gaff jaws to go up the mast it can only be stayed at the head, so it has to be a stiffer, heavier section with more air resistance.