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There's no shortage of good reasons to climb aboard a catamaran
Sailing a Cat: Attention to trim and reaching sails can provide a large speed bonus
To power the boats under sail, designers, with few exceptions, have settled on fractional rigs with small overlapping headsails and big, roachy, full-battened mainsails. This is a combination that's easy to control and keeps the center of effort low, which is helpful in obtaining maximum sail area while limiting, if not eliminating, the potential for capsize.
Small headsails keep headstay loads low. This makes backstays less important, to the degree that they can be replaced by upper shrouds led well aft, where, well outboard thanks to the wide beam, they don't interfere with the roachy mainsail.
But speed and performance aren't givens. "Four things make catamarans slow," says Gregor Tarjan of Aeroyacht. "Weight, of course. Then a dirty bottom, baggy sails, and an inattentive crew." That sounds a lot like the operating condition of many cruising boats, but at least a cat crew that pays attention can work to ameliorate any other deficiencies.
While the first impression gained on stepping aboard a cat and into the opulence of a fruitwood-trimmed saloon is of unabashed ease and luxury, these boats demand physical activity when under sail. In-mast mainsail furling has no place here-such a sail simply doesn't have the needed power or tunability.
Cat mainsails are big, and they're heavily built to withstand high working loads. Setting and stowing them requires effort (or help from the winches). Bigger mains go up on two-part halyards, and cat builders often provide a winch on the mast. An electric winch, or a convenient lead to the anchor windlass, can be a great help. The sail is usually stowed in a boom-mounted sail bag, but the high house and (frequently) solid bimini roof make packing it a relatively easy task, as long as access to the roof is simple and secure.
Trimming and steering a catamaran call for a delicate touch. Its great beam means a cat can be fitted with a long traveler with which to minutely control the set of the main, the boat's primary driving force. And because that force can be so powerful, midboom sheeting is unusual. Under way, the mainsheet is the safety valve, typically controlled on a winch mounted near the helm.
Changes in heel angle are so subtle that you have to focus on telltales and the speedo to measure the effect of sail adjustments. You'll also likely want to tack downwind, because achievable reaching speeds, even in moderate airs, are so much faster than sailing on a dead run.
For light windward work or moderate-air reaching, a reaching sail (variously called a gennaker, screacher, or code zero) can add knots and excitement. Set flying on a furler or, in the case of an asymmetric spinnaker, from a sock, it's easy to hoist and recover from the vast foredeck. Several builders offer bowsprits, and some support tacking the sail to the windward bow when off the breeze. On the Gemini 105Mc, an optional track spans the bows so the sail can be set to windward on either jibe without detaching the tack.
On any sailboat, the enjoyment you get from sailing is directly proportional to the effort you put into getting the best out of the boat. In the right conditions of steady breeze and flat sea and with an active crew, a catamaran can almost match a ride on a magic carpet.