Vessel hull types
To keep this simple – we’ll cover the three hull types. These are Monohulls, Catamarans and Trimarans [otherwise referred to as a type of multihull vessel].
a boat with only one hull, as opposed to a catamaran or multihull.
a yacht or other boat with twin hulls in parallel.
a yacht with three hulls in parallel.
a vessel with two or more, especially three, hulls.
We are continually asked what’s the best type of vessel to skipper and there’s no short answer. Personal preference is the major factor when deciding what’s best. With that in mind, we’ve compiled a list based on factual points. We believe that the catamaran is the way forward from a technical point of view. Its drawbacks are a higher initial purchase price, higher ongoing maintenance costs and if you’re inexperienced with catamarans, it’s easy to break them. Check below and let us know what your thoughts are in the comments.
Let’s start with level sailing. One of the first things I noticed when sailing a catamaran for the first time was the lack of heel. Even whilst powered up [under sail] or steaming [under engine] the vessel remained relatively flat in comparison to the traditional monohull. The days of bracing myself in the cockpit and living life being thrown around seemed to be behind me.
With the above said, it is important to look at the negatives and there’s a big one for sailing catamarans and trimarans. This lack of heel removes an element of awareness when putting pressure on the rigging. On a monohull we can use the vessels heel as one indicator to gauge the pressure we are putting on the rigging and often use that information to reef [reduce sail]. I’ve seen it time and time again where green catamaran skippers, who are unaware of how hard they are pushing their vessel, lose a mast or break something! All manufacturers supply written guidelines denoting apparent wind speeds that require additional reefing. It’s important you research and learn about your vessel prior to leaving for sea.
Multihulls are more stable than monohull vessels.
Monohulls can use the vessels heel as an indicator for rig pressure.
Multihulls are hard to gauge rig pressure due to the lack of heel.
All vessels come with written guidelines for sail plans vs. apparent wind speed.
Another reason why people love cruising catamarans is they will typically be around 30% to 50% faster than a cruising monohull of the same length. This means you’ll be cruising at the same speeds as racing monohulls, but with a gin and tonic in hand and all the comforts that come with a cat.
Trimarans are an entirely different beast, as they are often geared towards the performance end of the spectrum. Trimarans can regularly double the sailing speed of monohulls on nearly any point of sail.
Catamarans are typically 30% to 50% faster than a monohull of the same length.
Trimarans are typically built for speed and are able to get up to 100% faster than monohulls of the same length.
There are many aspects to safety where catamarans and trimarans excel. Let’s start with level sailing. It is much easier to keep crew aboard in heavy weather when the boat stays level and is pitching/rolling less. A large deck area keeps crew well away from the lifelines as well.
The speed of a multihull is another safety factor, as with decent weather information, it’s relatively easy to sail around or away from severe weather systems before they can bear down on you.
Should the worse happen and you reach the point of vanishing stability [capsize] the additional positive buoyancy a catamaran and trimaran offer almost guarantees the vessel will remain on the surface until rescue.
In addition to the above, both catamarans and trimarans are able to take on a substantial amount of water and still float. This is thanks to not only two or more hulls but the foam that is often used to fill dead space on the vessel.
The level sailing of a catamaran or trimaran provides a stable platform for crew to work on.
Faster speeds allows you to get out of the way of weather systems faster.
Catamarans and Trimarans offer greater buoyancy and as a result are significantly harder to sink [some claim it's near impossible].
Cruising catamarans and trimarans, with their straight and parallel hull forms and lightweight, enjoy excellent fuel efficiency when compared to monohulls, and track very straight. Catamarans almost always have twin engines, which allow for tremendous control in close quarter situations. In fact, with practice, it’s possible to get the vessel spinning on the spot or crabbing sideways. Try that on a monohull. Prop walk is minimal or nonexistent as well, and the redundancy of a second engine is appreciated should a mechanical issue arise underway. Nearly all trimarans have just one engine, so the differences are minor when comparing them to a monohull.
The twin engines of a catamaran makes it more manoeuvrable than a monohull or trimaran.
Having two engines provides a redundancy against engine failure.
Catamarans are faster than trimarans and monohulls when steaming [under engine] and are often more fuel efficient.
Crew and Living Space
No doubt you’ve already realised the enormous gains in living space afforded by modern cruising cats. Typically a cat will have space below equivalent to a monohull 10+ feet larger. When combined with added cockpit space, possibly a flybridge, and more than doubling the deck space, it becomes a whole different ball game. It’s important to note that you not only gain a tremendous amount of space, but nearly all of that space if very liveable and comfortable, whether at anchor or underway. It should be noted, however, that trimarans don’t show an increase in interior volume, and in fact tend to be smaller below than monohulls of the same size. This is mitigated some by the additional storage in the hulls and added net space, but the narrower, performance-oriented main hull tends to be less than palatial.
Catamarans offer much more space than a monohull of the same length, often with additional decks and even a flybridge.
Trimarans tend to be smaller below than a monohull of the same length.
Shallow draft / drying out
Because multihulls’ stability comes from it’s increased beam from an additional hull, there is no need for ballast or a large keel. This reduces overall weight and, importantly, draft as well. It is common for a 40+ foot cruising cat to have a draft of less than 1.5 meters, allowing sailors to explore shallow areas monohullers fear to tread. Fancy the Bahamas or the Great Barrier Reef? No problem. If you have some quick underwater maintenance to do (replace prop shaft seals, zincs, a through-hull), catamarans can be dried out at low tide on a flat area of sand or solid ground, such as a beach or slipway. You can also nose right up to that perfect beach if the weather allows. Trimarans typically have no keels at all, and instead rely on a centre-board to prevent leeway [similar to that of a dinghy], making them perfect for drying out on that dream beach.
The reduced draft of a catamaran and trimaran means they are able to explore shallow seas which the traditional monohull can't get to.
Catamarans can by dried out on any flat and stable surface such as a slipway or beach.
Trimarans are also perfect for drying out on any flat and stable surface.
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