Adding Additional Area Aloft When Sailing a Cat Downwind
Cruising multihulls lose a lot of their pizzazz when your destination is downwind, unless you add some additional area aloft
Modern cruising catamarans make it easy to head off into the wild blue. Whether it’s a daysail to Discovery Island for a Pacific-coast picnic or a tradewind passage from the Cape Verdes to Antigua, you can count on a cat to keep you comfortable with plenty of elbow room. Speed, too, is usually a bonus. But because most cruising catamarans have conservative sailplans designed to keep their crews out of trouble, you’ll need specialized sails to keep your cat scrambling downwind and in light air.
On a recent passage from San Diego to Honolulu aboard a Leopard 46, I found a used spinnaker pole at a marine consignment store and rigged it so I could pole out the jib and sail wing-and-wing for days on end. My crew and I were able to make reasonable time in pretty strong winds, and the autopilot had no problem steering, because we were sailing straight down the waves, rather than gybing from broad reach to broad reach—tacking downwind—and taking the big tradewind waves on our quarter.
Most cats cruise near the coast in light to moderate wind and moderate or calm seas. Tacking downwind, what racers call “sailing angles,” is a pleasurable way to make progress when your destination is dead to leeward, because the skipper can keep boatspeed up while the breeze keeps the crew cool. Most cats don’t carry spinnaker poles, because they get in the way and are a hassle to rig, so sailing wing-and-wing isn’t a viable option.
“On a typical cruising cat, to make the best progress downwind, a full, round asymmetric spinnaker is the answer,” says Charlie Enright of North Sails. “The skipper should sail as far off the breeze as possible while still keeping the sail drawing.” Figure on an apparent wind angle of about 140 to 150 degrees. Velocity made good (VMG) usually won’t be improved much by heading up for more speed. Charlie says he’d use a snuffer to make setting and dousing the sail easier.
Designer Chris White’s Atlantic series of catamarans are much more performance-oriented than a typical cruising cat designed for the charter trade. He says cats are at their weakest dead downwind, but points out that setting a flying sail is time-consuming and a pain in the neck to lug around on deck, so anything a skipper can do to make the process easier is an advantage.
Currently, his preference would be to set the fullest sail that could be furled. Chris points out that “sprits are normally fixed on the centerline of the boat, so it’s easy to blanket the spinnaker behind the main if you’re sailing low. Moving the tack to the windward bow will help.”
Because few cruising sailors bother tacking downwind, he says he would consider setting a symmetric spinnaker on a tradewind passage, such as from the Canary Islands to Antigua. Many catamaran designers and builders incorporate a short centerline sprit to get the spinnaker forward of the sailplan, which works really well when you’re reaching above a 140-degree (or so) apparent wind angle.
On some cats, you’ll find three headsails furled on the centerline. The inner sail is normally a heavy-duty Solent, a non-overlapping jib that is usually set on a fractionally-rigged stay or furler that may not tack all the way forward. On the center stay you may find a lighter, large, genoa-like sail called a screecher that is cut quite full, sports a straight luff and overlaps the main. In light air you can use it to make good time to windward. All the way forward, at the end of a sprit, is a round-luffed asymmetric spinnaker that is deployed when sailing at apparent wind angles of about 110 to 140 degrees. On a two-week cruise you might choose to leave all sails up and furled until you got back home.
In winds less than 12 knots or so, a racing or fast cruising multihull will almost always sail downwind with the apparent wind forward of the beam. In a light to moderate breeze, every point of sail feels like you’re close-reaching or sailing upwind when you’re aboard a fast cat. Sails for such boats tend to be flatter, with straighter luffs, than those found on more sedate cruisers. These flatter reaching sails are usually constructed from Dacron and incorporate a UV cover, though on many higher performance multihulls, lightweight, high-tech laminates such as Cuben fiber are preferable.
Most running sails—both symmetric and asymmetric—found on cruising multihulls are made from the same nylon fabric that’s been used for years in spinnakers. As UK Sails’s Butch Ulmer says, “Cruising multihulls are heavy-displacement boats, so they are not particularly fast. Thus, the shape of the downwind sails isn’t any different. However, the stability of these boats is far greater than a monohull, so the sails are more heavily loaded whenever the wind is from the side as opposed to astern. This translates into the need for a material that is less stretchy and has a greater tensile strength.”
“In winds under 25 knots, when the apparent wind gets aft of 90 degrees, the typical cruising multihull is going to need some kind of downwind sail,” says Multihull Company president Phillip Berman, who has extensive experience cruising on catamarans. “I don’t believe in asymmetric sails on cruising cats,” he adds. “On my own boat, I like a big symmetric spinnaker tacked to both bows to pull me swiftly downwind.” He’s a big fan of the ATN spinnaker sock for keeping the kite under control while hoisting and dousing. His ideal sail inventory would also include a Dacron screecher set on a continuous-line furler. He sees the screecher as a versatile reaching sail that can be used upwind in less than 8 knots of wind to get a boat speeding along without having to resort to the engine.
For furling sails set on a sprit, Gunboat founder Peter Johnstone recommends keeping a turtle bag on the centerline and lowering the furled sail straight into it. “The bagged sail takes up very little room,” he says.
“Setting a spinnaker from a sock is easy if you bear off and blanket it behind the main as you hoist and douse the sail,” suggests Phillip Berman. “I see too many boats coming in for sale where the owner has never used his spinnaker, and that’s a pity.”
A delivery skipper and freelance writer who has logged more than 300,000 offshore miles, Andrew Burton recently delivered a Leopard 46 catamaran from Florida to California to Hawaii