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One hull or two?

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Join SAIL staffers in a side-by-side comparison of a 33-foot catamaran and a 37-foot monohull.


Are apples better than oranges? Is Coke better than Pepsi? Any answer will depend on personal preferences. The same holds true in the catamaran-versus-monohull debate. Each has its pros and cons.

Generally speaking, a cruising catamaran has more interior volume and better offwind speed potential than a monohull of similar size. On the other hand, many cruising monohulls have superior upwind performance. Monohulls heel. Cats don’t—a selling point for many people. Many catamarans are shoal-water friendly, while most monohulls are constricted by deeper draft. A monohull will tell you through excessive heeling and weather helm that it’s overcanvased and will provide a sensation of acceleration, while some cats give this information only through the instruments.

Many cruising cats have a bridgedeck saloon that’s directly connected with the action in the cockpit; monohulls have accommodations inside the hull. The helm stations on some cats have visibility issues; most monohull helm stations have excellent visibility. Cats have wide, flat decks and seem to have unlimited deck space; by comparison, a monohull’s deck space is more limited.

To see how these differences played out in an actual cruising situation, we looked for a production monohull and a catamaran with similar volumes and similar prices the kind of boats many people buy for coastal cruising.

The 33-foot, 6-inch Gemini 105Mc catamaran and the 37 foot Beneteau 373 monohull met our criteria, so we set off for a few days of late-fall cruising on Maryland’s Chesapeake Bay to compare the apple and the orange. We put both boats through the exact same situations. Here’s what we found.



We had just set sail when a squall packing 25-knot gusts and driving rain rolled in. Both crews tucked a reef in their mains and wound in several turns of headsail. Close-reaching under shortened sail during the short blast of 18-to-25-knot winds and moderate Chesapeake Bay chop, the Gemini logged a top speed of 9 knots and the 373 recorded speeds close to 8 knots. Once the squall passed and the wind diminished to 12 to 15 knots, both crews shook their reefs out and began some informal two-boat testing. The 373 recorded close-reaching speeds in the 6s and 7s; the Gemini recorded slightly faster speeds. When the wind dropped to 5 to 10 knots, the speeds of both boats dropped into the 4-to-5-knot range.

Sailing side-by-side revealed differences in speed, motion, helm feel, and pointing ability


The Gemini got a boost from its screecher in the light stuff. It was easy to keep the cat on track, but the helm feel was somewhat muted. The 373’s steering system has a relatively short run to the rudderstock and hence a more positive feel.

The Gemini performed well in the reaching conditions, but it was evident when both boats went hard on the wind that the Beneteau was able to point about 5 degrees higher. In 8 to 10 knots of wind (we chose not to bash to windward in the squall) the 373 logged speeds in the mid 5-knot-range, while the Gemini hit speeds in the low-5 knot-range. Each boat had a pleasant but very different motion through the water. The 373 rewarded proper sail trim and a steady helmsman with a tactile sensation of speed and a manageable heel angle. The Gemini trucked along without heeling, but, like many cats, had a more abrupt motion and was prone to bridgedeck slap.

Verdict::We liked the stable platform provided by the cat, and we liked the sensation of sailing the monohull.


The monohull’s helmsman had excellent visibility (left). The cat’s helmsman sat outboard of the pilothouse to see the jib telltales (right)



Each cockpit comfortably accommodated our crew of five. When it started raining, the crew of the 373 scrambled for foul-weather gear, while the crew of the Gemini was protected in the cockpit beneath a full-length hard top and clear plastic side curtains (an option). However, when it was time to work with halyards and reefing lines, which lead to the base of the mast, the Gemini crew got equally soaked and they had to move more cautiously on its narrow side decks. The 373 helmsman enjoyed unencumbered visibility from the cockpit; on the Gemini, the helmsman’s view from the bulkhead-mounted helm station was compromised by the coachroof bulkhead and the pilothouse.


Both cockpits had comfortable seats, adequate stowage, and plenty of space for our crew of five. Cat (left); mono (right))


The helmsman on the Gemini had several steering options: sitting in the helm seat and looking through a large opening bulkhead port and then through the pilothouse; sitting outboard of the pilothouse and steering like an engineer on an old-fashioned locomotive; or standing with his head poking out of a hatch in the hard top. All required a bit of getting used to and posed visibility challenges. Steering the 373 was straightforward and comfortable from both the sitting and standing positions.





Lounging space

Along with comfortable cockpit benches, the Gemini has loads of “loungeable” deck area. It doesn’t have the trampolines between the bows that many other cats have, but its hard, flat deck provides stowage as well as ample sunbathing space at the expense of some added weight. It has a seat built into each bow pulpit and a clever and comfortable “couch” made of mesh fabric integrated into the dinghy davits. The cockpit benches on the 373 are long enough to stretch out on and the side decks are wide. However, it lacks the stern-pulpit seats you see on many cruising boats these days, and anyone looking to lounge forward of the cockpit has to contend with the cabintop. Verdict: No contest. The cat scores for its superior deck area and taffrail “couch.”


The 373’s pivoting steering wheel (left) and the Gemini’s taffrail “couch” (right) are both clever and effective ideas


Clever features

To free up more room in the cockpit and make the walkthrough stern easier to access at the dock or at anchor, the 373 is one of the first Beneteaus to be equipped with Goiot’s pivoting steering system. You pivot it out of the way (and lock it back into place) simply by pulling a knob on the steering post. The Gemini is equipped with an optional curved screecher track running between its bows. It allows the screecher tack to be easily hauled up to windward for maximum offwind efficiency. Verdict: It’s a draw. Both boats benefit from creative thinking.




The Gemini’s galley has considerable counter and stowage space (left). The 373’s galley is more compact (right)



We hung out in the Gemini’s saloon when it was raining and after we had rafted up for the night, even though the 373’s saloon had a more open layout and, in places, superior headroom. This was partly because the Gemini’s saloon opens out into the cockpit and also because the multiple ports and the large pilothouse windows provide visibility and good ventilation. The saloon sole measures 66 by 39 inches, excluding the dinette area. Six can sit at the 30-by-44-inch dinette table; there is an additional seat next to the companionway door. There is ample standing headroom under the pilothouse, although the dinette itself has only sitting headroom. We did our trip planning at the dinette table; the stand-up nav station in the port hull also has a table big enough to accommodate a chart book. The dinette can convert into a double bunk or perhaps serve as a child’s play area as its close proximity to the helm station would make it easy to keep an eye on small kids.

The 373’s saloon was bigger and more comfortable than we imagined it would be. It was bright and airy thanks to three fixed ports on the forward edge of the cabintop, two opening ports, and two opening hatches. The 373 has much more freeboard and—get this—only 20 inches less beam than the Gemini. All that volume is there for one reason only—interior comfort. The saloon is big enough to accommodate 10 people for drinks; headroom is 6 feet, 6 inches throughout; the dinette table measures 33 by 40 inches, and the seats are over 6 feet long and form two excellent sea berths. The saloon is also equipped with a sitdown nav station; the chart table measures 18 by 32 inches. The entire accommodations plan is finished with varnished teak-veneer woodwork. Verdict: The cat has a better view from the saloon, but the monohull has a slight edge in headroom and overall comfort.



The Gemini’s galley, located in the starboard hull, has everything a cruising chef looks for: long counters on either side of the hull, pressure water, a propane stove with oven, and 4-cubic-foot front-loading refrigerator/freezer that is large enough for a much bigger boat. The fridge can run on propane or shore power and froze our water bottles solid overnight. As the photo shows, there are excellent brace points and a wonderful view outside as you toil away. The 373’s L-shaped galley and conventional top-loading 12-volt reefer are comparatively small. There’s room for only one cook. Putting in the sink covers increases usable counter space, which is divided between countertops measuring 21 by 26 inches over the reefer and 11 by 23 inches next to the sink. Verdict: For counter space alone, the cat gets the nod.



The consensus was that both boats have comfortable, functional berths, adequate standing headroom, sufficient ventilation (the forward cabins were better than the aft), and areas where you could bump your head if you weren’t paying attention. The 373 we tested was the three-cabin version (a two-cabin version with a large sail locker is also available); the forward cabin is slightly larger, but not enough to spark a “Your cabin is better than my cabin” debate. The forward-cabin V-berth measures 66 by 79 inches but tapers to 16 inches at the foot. The standing dressing area at the head of the berth measures 18 by 45 inches. The 78-by-55-inch aft cabin berths taper to 44 inches at the foot.


The Gemini’s dinette is cozy, close to the cockpit, and let us see outside (left). The 373’s saloon has a bit more headroom than the Gemini and is more isolated from the cockpit (right)


The Gemini’s cabins are more removed from the action in the saloon. The rectangular berth in the main cabin forward of the saloon measures 78 by 59 inches with standing headroom along the entire length of the berth on the starboard side. The aft-cabin berths measure 74 by 46 inches. Verdict: Close, but the larger forward cabin gives the edge to the Gemini.



The 373 has bookshelves along the hull on each side of the saloon as well as one locker measuring 5.8 cubic feet. There is some stowage under the settee seats. The galley has 11.5 cubic feet of locker space, plus a flatware drawer and a hinged trash compartment. The forward cabin has a narrow shelf along the hull, some stowage under the bunk, and a 9.7-cubic-foot hanging locker. Each aft cabin has a narrow shelf along the hull, stowage areas under the bunks, and a 6-cubic-foot hanging locker.

The Gemini has a large locker under the saloon settee.

The galley has a stowage area under the stove for pots and pans, a narrow shelf along the hull above the stove for mugs, and a large 60-inch-long locker built into the countertop adjacent to the sink. Additional galley stowage—drawers for silverware and other utensils, along with a shallow locker for plates and dry goods—is built into the back of the saloon settee. Forward and aft buoyancy tanks affect usable stowage somewhat, and the space under the aft cabins is occupied with water tanks, but there is still considerable stowage space left over. Each aft cabin has an 8-cubic-foot hanging locker, a smaller locker measuring nearly 2 cubic feet, and a 2-cubic-foot drawer. The hanging locker in the forward cabin takes up the entire starboard bow. The forward cabin also has four large bins along with another locker.

Verdict: The cat has more stowage space. In general though, overloading a cat can affect performance.



Our side-by-side sail-off revealed that both boats have comfortable accommodations, interesting features, and perform well under sail and power. The cat has more deck space forward and is better suited to shoal-water cruising. The monohull has better windward performance and more headroom in the saloon. We liked the visibility from the Beneteau’s cockpit, but we also liked being protected from the elements in the cat’s cockpit. The cat has a bigger galley, more stowage, and may be better suited to living aboard. The monohull has a sit-down nav station and could easily find competition on a racecourse.

The variable-draft cat could go where the fixed-keel monohull feared to tread


A comparison of the scaled accommodations plans above reveals that these boats use similar interior volume in very different ways. However, the difference between catamaran and monohull interior volumes increase dramatically as the boats get larger.

The bottom line is: What do you want your cruising boat to do for you? If you’re looking for a thin-water-friendly, level-sailing cruiser with loads of deck space, comfortable cabins, copious stowage, and a saloon with 360-degree visibility that connects directly to the cockpit, a cruising catamaran is for you. If you’re looking for a traditional cruising boat with comfortable accommodations—and if windward performance is more important to you than a 360-degree view from a bridgedeck saloon—a monohull will be your best choice.



               January 2004



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