Comparison of Catamaran and Monohull

We read several good articles and books about the difference between sailing a cat and a keelboat and found them helpful. Some of their generalities didn’t apply directly to our experience so the following is our comparison between the Privilege 37 catamaran and the Moorings 413 (Beneteau 411).

Similarities: Both boats had three staterooms and two heads. One of the heads was in the master stateroom. The master stateroom was forward and the two smaller staterooms were aft.

Comfort: With 22 feet of beam, the catamaran offered more space in all areas. Particularly the aft staterooms were far more comfortable and had good storage. There was an area in the starboard hull with storage on both sides. The galley was down in the port hull but it was open between the galley and settee so the cook was not excluded from conversation. Storage and accessibility in the master stateroom was better in the Beneteau,

 In the monohull the galley was right on top of the settee and people getting in or out crowded the cook.

Two people in the galley of the cat was cozy but two in the monohull was nearly impossible.

Under sail there is a big difference in comfort. You are still on a boat and those members of our crew that were prone to seasickness the first couple of days last year, had similar discomfort at first this year. Since the boat is not heeling hard, through-hull fittings can be left open. Going below to use the head in a monohull heeled over hard is unpleasant. Everything is slanting and it is hard to move around. You have to bend over in the confined space, open the through-hull, sit on a sloping seat and hope you don’t get splashed, and after flushing, go through the acrobatics of closing the through-hull again.

On the cat, I went below, moved around with not much more effort than walking on an airliner in mild turbulence, did my business, flushed and returned without that queasy feeling.

The cockpit on the cat was larger and the foredeck easier to get to and use. Gearing up for diving was easier due to the extra space. The swim ladder on the Privilege was poor and getting back from a dive, swim, or snorkel was a hassle. Raising and lowering sails felt safer with the wide area available to stand.

Under sail: I love having the gunwales in the water, the sheets howling in the wind, occasional water over the bow, and working against a weather helm. Now that is sailing! On the cat, the sheets do howl in the wind, but the rest of it seems too darn easy.

As a direct comparison, we were sailing to Gorda Sound, going east up the Sir Francis Drake Channel. The apparent wind was about 45 degrees off the starboard bow. A Moorings 413 was also reaching upwind but was probably reaching 10 degrees higher than we were. There was decent wind (about 10 knots apparent) and we were making only slightly better speed than he was. The monohull was heeled over hard and he was making an erratic path through the water as he fought the weather helm. We had the autohelm set, and were cruising along effortlessly and nearly level. I turned up wind about 10 degrees and paralleled his course, still sailing slightly faster than he was. Each time the weather helm got the best of him, the boat veered to starboard and reduced the distance between us. To give him some sea room, I slowed the boat, cut behind him, retrimmed sails and passed him on the down wind side.

His sail was more exhilarating than mine but he was working much harder, and except for the excitement, I can’t believe his crew was as comfortable as those on our boat.

 I had expected that coming about might be tough and that sailing up wind would be disappointing. Actually, there was plenty of momentum to bring the boat about in all but the lightest winds. Our boat was apparently meant to be cutter rigged with an extra forestay but did not have a staysail. The Genoa wanted to catch on the extra forestay and that was the hardest thing about tacking.

The Privilege, with fin keels along the hulls, seemed to have pretty good directional stability and would point close to 30 degrees. Pointing that tight cost a lot in terms of boat speed and I tried to keep it closer to 45.

The shallower draft was a definite advantage in anchoring and cutting through passages where deeper draft boats could not go.

Under Power: The big keel on the monohull gave great directional stability so it was very responsive to the helm. Using the wheel and the effects of throttle and prop walk, I could maneuver the monohull into some pretty tight places. The cat with its two small keels was not quite as responsive to the helm, but the two screws mounted about 20’ apart in the hulls makes it possible to do things I would never consider in a monohull. Using the two throttles in various combinations of forward and reverse was like playing a video game. Of course, power boaters who are used to twin screws are not surprised by this. We did not have counter rotating props, but I never felt the need.

Visibility: One place the monohull is clearly superior is in visibility from the helm. The high cabin and placement of the helm behind it on the port side made it very hard to see moorings or anything up close. Bringing moorings up on the port made it a little easier. Some cats have dual helms but they seem to have throttles on only one side, and since maneuvering in close quarters tends to be done with the engines, that is not much help.

Another aspect of visibility is the ability to see the sails. With our helm on the port side, when we were on a starboard tack, the boom and mainsail blocked the view of the sails from the helm. With a monohull and a central helm, the sail is never directly over the helmsman and a clear view of sail trim is easy. In this case, twin helms would solve the problem.

A friend of ours built a custom cat and put the helm forward of the cabin. He has a great view. We have seen only one factory boat or stock design with this feature. He doesn’t have the cabin to hide behind in weather, but with the good visibility he can move into the cabin and use the auxiliary helm. Our boat could have been maneuvered from inside the cabin using the autohelm to steer, but the view from the cabin was limited at best.

Summary: The low silhouette and graceful lines of the monohull are more pleasing to my eye. The feel and feedback a monohull gives the sailor is unmatched by the cat. Still on balance, the comfort, convenience, and sometimes speed of the cat far outweigh its shortcomings. In short, we are catamaran converts.