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Old 10-05-2004
Kevin Jeffrey Kevin Jeffrey is offline
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Cruising Multihull Sail Trim


Since the days of the early Polynesians, multihulls have come a long way in design, aesthetics, and performance.
Although my wife first introduced me to the world of sailboats aboard her father's Sparkman & Stevens 35-foot wooden sloop, I learned the art of sailing in 1980 as co-captain of our own cruising catamaran, a Heavenly Twins 26.  That wonderful craft was to become home for us and our young twin sons for the next four years, taking us from Cape Cod to Florida and repeatedly to the Bahamas.  Our next boat was an older Prout catamaran that we bought in the Dominican Republic and cruised eastward to the Virgin Islands.

As a confirmed multihull sailor I'm often asked, "What is sailing and sail trim like on a cruising multihull?"  To a large extent that depends on your level of sailing expertise, on the boat you sail, and your perspective. Since the basic sailing concepts apply to multihulls as well, you'll find the experience similar to monohull sailing with subtle but important differences that we'll review in this article.

Being new to sailing, I had few preconceptions about how a sailboat should perform.  My wife, despite growing up crewing on her father's sailboat, was also new to making the real decisions about sailing and sail trim.  Those sailors in circumstances similar to ours will find that multihulls are relatively easy, forgiving boats to learn on, and you won't be trying to subdue years of monohull sailing instincts.  Learning to sail and becoming proficient at sailing a multihull will be one and the same. Experienced monohull sailors, on the other hand, will have a firm grounding in the basics of sailing, yet they'll need to get over the mindset of always comparing multihull sailing to sailing one-hulled ballasted boats.


The author's first multihull. While slow by contemporary standards, it could still post speeds of 10 knots.
The boat you learn on tends to become your benchmark for what multihull sailing is all about, though performance and handling varies remarkably between various designs.  Despite the huge strides in market acceptance over the past few years, there is still a tendency to lump all multihulls together.  My wife and I learned on a true cruising boat, one with no pretensions of high performance.  She had a 26- foot LOA and 14-foot beam , almost no heel and, though considered a slow multihull, was able to sail at speeds up to 10 knots.  Sailing our Heavenly Twins was much like sailing other cruising catamarans of modest speed, but still very different from sailing a high-performance cruising multihull.

Your perspective on what sailing is all about also influences your approach to multihulls.  A relative once told me that you weren't really sailing unless you were cold, wet and tired.  If you can relate to those sentiments, you may be disappointed with sailing a multihull.  I personally couldn't disagree more, having always taken great pleasure in the comfortable, protected sailing conditions and quick passages a multihull affords. Let's review some considerations and techniques for sailing multihulls in normal sea conditions.

Sailing Fast and on the Level    One of the first things you notice is the lack of heeling on a cruising multihull.  There's no need for constantly bracing yourself and your gear at unnatural angles.  Sailing is more comfortable and less tiring, which should translate into more enjoyment and safer operating conditions on the water.


Flat and fast means shorter and less fatiguing passages, although feedback from the helm may be an issue for monohull sailors who making the transition.
Searching for a downside to level sailing, I'd say there's a lack of feedback that heeling provides the helmsman.  With no appreciable heel and a reduced tendency for weather or lee helm on a multihull, it's more difficult to tell when it's time to reduce sail.  You have to rely on boat speed and boat motion relative to the seas.  Multihulls have no real ability to spill a gust of wind by heeling; they typically translate excess wind energy into acceleration, something that takes a little getting used to.  Rapid acceleration is most noticeable on light displacement multihulls with high-performance rigs.  I thought I knew what boat acceleration was until I sailed a 31-foot trimaran sport cruiser.  She went from six to seven knots to 12 to13 knots in the blink of an eye; quite normal, I later discovered, for high-performance cruising multihulls.


While this high-performance trimaran is an entirely different animal than your average cruising cat, it illustrates the fact that any time speed increases on multihulls, apparent wind moves further forward.
Cruising multihulls not only accelerate quickly, they maintain higher average speeds than monohulls, though many in the industry overstate the case.  Slower cruising multihulls sail like fast monohulls, only with higher top speeds, so sailing and sail trim is comparable. High-performance cruising multihulls, on the other hand, can attain speeds of 20 knots or more.  Sailing at those speeds is quite different, partly because everything happens much faster and partly because the apparent wind is brought far forward, to the point where a broad reach on a monohull becomes a close reach on a fast multihull, and a beam reach becomes close-hauled sailing.  Most cruising multihulls on the market fall somewhere in between, so as a rule you can expect to maintain smaller sheeting angles and flatter sails for a given true windspeed than on a monohull.

In Part Two of this article we'll continue to explore the fun and challenges of sailing and sail trim on a cruising multihull.