I get a lot of questions from future cruisers looking for a boat. Many of these people are hung up on the monohull vs. catamaran dilemma. Though most of us learned to sail on single-hulled boats, both monos and cats have been around since man thought up the idea of taking wood to water. It is only recently that cats have really flourished in the cruising world. To me, the choice comes down to what kind of cruising experience you are looking for. And between cats and monos, the old saying is especially true, "Choosing a boat is all about compromise".
In my 36 years, most of my sailing has taken place on monohulls. I learned most of what I know about our double-hulled friends when I skippered a new 42' Catana on a 4000 mile epic (in my mind) voyage from France to the Caribbean. On that adventure, my crew and I encountered a surprising array of conditions.
Cruising speed: We had a few choice, mostly accidental, bouts with unbridled acceleration but that was not the norm. For our Atlantic crossing, on our nearly empty modern cat, we averaged about 8 knots. We weren't racing, though much of the time we had as much sail up as we dared. The average speed wasn't much more than a monohulled cruiser of the same size. Another thing to consider: you can load monohulls to the gills and it will have minimal affect on speed. Cats are a very different story.
Beating: You may not think that the ability to beat is important in cruising. That is unless you have been in the unfortunate position of having to claw off a lee shore in heavy weather. It was a beautiful sunny day off the southern coast of Spain. We were on our shiny cat trying to make Gibraltar by nightfall. There was a strong breeze blowing onto shore. The wind had kicked up a nasty three-foot chop. If I were in a monohull, I would have worked up into the wind, pointing high as we rode up the crest of the swell, falling off the wind as we rode down the back of it taking advantage of the shape of the back of the wave to shoot us forward again. However, on a cat there is no graceful way to claw off a coast through steep swells. With both engines blazing, boards down and a good amount of sail up we couldn't gain from the coast. We could get one hull to carve nicely but just as we started to make headway, the opposing hull would slam into the next swell. It was like shoving a shoebox through a keyhole.
Later, off the coast of Morocco, we found ourselves beating into twelve-foot swells, the hulls creaking and grinding, forever trying to undue their unnatural pairing. The owner of the boat, who was helping in the delivery, would later tell me, "If I thought that paying a million dollars would have gotten me off that boat, I would have paid it." There's a money-making business in there somewhere.
Stability: We were surfing downwind en route to the Caribbean. I was sleeping. The owner decided to try wing and wing … at three in the morning … in a near gale. I awoke to the cat skipping sideways through the water. If the boards were down or if the hulls had keels, who knows what would have happened.
Cost: There is the concern of finding parking at marinas, at any cost for the beasts. As you would imagine there are two of most everything on cats. They can be double the cost of a similar sized monohull. That is, unless you are talking about a very well built monohull. Which brings us to …
Integrity: I hung out with Lats contributor Jo Djubal and her husband when we were hauled out in Australia. They cruise on a cat. They were doing some work to a hull and I was surprised to see how thin the cored hull was. Even my coastal cruiser had a solid glass hull an inch thick. My friend Warren just sent me a story about a family that sailed off into the sunset on a modern 55' cat. But the story didn't end there. The big cat hit a reef and when it did it tore the bottom out of the boat. The boat lost some of its integrity, which allowed the rig to give way, falling on the skipper and severing his leg. By morning, the entire cat had nearly disintegrated. Many mistakes have to be made before you'll find yourself on a reef. The point here is that most monohulls that wash up on reefs still float when they get dragged off.
Comfort: Let's just say that the motion is different between a cat and a monohull. While a mono can be rolly (very much so depending on the design) cats stay mostly upright. Some complain that the jerky motion of a cat is uncomfortable to them. It's never bothered me. I should point out that while sailing the cat there were times I didn't sleep well. It was always in the back of my mind that the boat could flip over. All boats can flip over. It's the staying upside down feature of a cat that concerns me. I hear the point that people make about how cats don't sink when they are upside down, that the crew of a cat can survive on the upturned hull when inverted. Just thinking out loud here: if conditions were grand enough to flip a cruising cat, survival of crew strapped onto a slippery exposed stretch of fiberglass must be challenging at best.
Fun: I've heard people tell me that they think my priorities are out of whack. When I went to sea in a coastal boat instead of waiting to be able to afford a safe boat, people commented. And maybe it was wrong for many, just not for me. To me, the first thing a boat should be is fun. To me, the potential speed of a cat; the gigantic on-deck party area; the all around viewing ability of the raised saloon; setting my beer down on a flat surface at 24 knots and not worrying; is a good time … to me.
I've heard it on both sides. One's better than the other. Truth is, they are completely different, and I like 'em both. If pressed, I'd tell you that for serious, though restful, rough-ocean passages, I'd take a monohull. However, for living it up in high-style 'round the islands, my choice would be a cat. But I'm in it for the islands. Since it is my personal cruising style to give up a little at-sea safety for a faster passage in order to extend my island time … I'd try a cat.