When it comes to hot debates in the sailing and cruising community, this one probably ranks right next to, "Which type of anchor works best?"
And the answer is...it depends. There are many variables to consider when trying to decide on the right answer for your needs, including your intended sailing grounds, budget, priorities, and perhaps most of all, personal preference.
In this article, we are going to take a look at the top 5 advantages for choosing a monohull or catamaran/ multi-hull. While we can't possibly cover all the considerations or the multitude of designs, here are some general guidelines to help inform and refine your search:
1. Cost of Ownership - the initial and ongoing cost of a monohull is usually close to half that of a comparably sized or smaller cat. Docking cost, especially if you plan to dock frequently in a marina, maintenance and survey haul-outs, and dry docking are all less expensive for a monohull. Many multi-hulls also have two engines, which requires twice as much fuel (see more on this topic under Cats), maintenance, and spare parts. More creature comforts found on big cats also come at a cost of price in terms of maintenance and the propensity for issues. Remember, Murphy loves boats!
2. Windward Performance - while there are some multi-hulls that have decent windward performance, self-tacking headsails, etc. these are generally exceptions to the rule. Monohulls generally perform much better when sailing close to the wind and in terms of tacking. This simply affords more options and faster passages when/ if your next waypoint requires sailing to windward.
3. Heavy Weather - monohulls and multi-hulls employ very different maneuvers in heavy air and storm tactics. Fortunately, modern weather forecast apps help mitigate, but does not eliminate, the risk of getting caught by surprise. In terms of advantages, monohulls have the ability to "heave to" or "run-off". Since there is only one hull, the stress of a heavy sea and the motion is typically better weathered on a monohull. Also, monohulls are typically self-righting in the event of a knock-down or if the vessel were barrel rolled (worst case scenario). Once a catamaran is upside down, it will stay upside down, and no one wants to be caught in that situation in the middle of a large ocean with breaking seas.
4. Width - a monohull between 30 - 50ft LOA will have a beam (width) that is approximately half that of a comparably sized cat. While many marinas have slips and equipment to accommodate multi-hulls, this is not always the case and there are generally fewer spaces available since they have to be twice the size of a normal slip. Monohulls obviously do not have this problem. Also, navigating in and out of a crowded anchorage, a narrow channel, or a tight marina is generally less challenging in terms of width for a monohull. More on maneuverability later.
5. Motion - while a catamaran has a very smooth ride and little to no heeling in normal sailing conditions, the motion in heavy air and big seas, the ride is a lot less comfortable and many report the tendency to get seasick more quickly. A monohull will pound a lot less in a seaway. Since there is only one hull with deeper keel and ballast, a monohull has a tendency to maintain it's momentum and ride out a heavy sea better than a cat.
1. Comfort - under typical sailing conditions, it's hard to beat the comfort and stability of a catamaran or multi-hull platform. While some sailors prefer the motion and feel of a monohull, many find the lack of heeling more reassuring, especially when moving about on deck. A large center saloon with large seating area, protected panoramic view, and large deck area are also compelling qualities.
2. Speed - cruising catamarans are faster than monohulls and can average half the speed of the wind, depending upon the angle. It’s ideal to be on a boat that is both fast and stable, allowing you to make passages in a safe and timely manner. Cats are also very fuel efficient in fair conditions due to less wetted surface.
3. Buoyancy - catamarans use their wide beam for lateral resistance and stability instead of a keel or ballast, so cats are naturally more buoyant than a typical monohull. This also makes them virtually unsinkable. While they can capsize or pitch-pole in the worst case scenario, the boat will likely remain floating on the surface. If the conditions have deteriorated this badly, being on the water clinging to the hull is a sketchy scenario but still beats sinking.
4. Maneuverability - cats usually have two motors, one on each hull. This affords a huge advantage in terms of ease of maneuverability and eliminates the need for a bow thruster. Also it means redundancy in case one engine fails. You can turn a cat on a dime by putting one motor in forward and the other in reverse. Arguably, an experienced skipper can manipulate prop walk on a monohull to do the same, but this is a more difficult maneuver for a monohull.
5. Draft - a catamaran draws very little water (hull depth below the surface) and can venture with confidence into anchorages where no fixed keel monohull would dare. You can literally beach a cat and then shove off in only a few feet of water. If your cruising grounds are primarily in shallow waters of the Carribean islands or gunk-holing in the Chesapeake, a cat has some serious advantages.
This is a cursory overview on a choice that is largely about personal needs and preferences. We hope you find this information informative as you consider your next boat purchase. Of course, we'd love to hear your opinions and don't forget to shop our selection American Made sailing apparel.