Monohull vs catamaran
A catamaran gives space and flat sailing. A monohull points higher and costs less to berth. Berth width often decides it.
Updated 3 min read
Key points
- A catamaran has far more living space than a monohull of the same length, and it barely heels.
- Marinas price and allocate berths by size, and a catamaran is much wider than a monohull of equal length.
- A monohull points higher into the wind. Most cruising catamarans motor more.
Space
A catamaran puts the cabins in the two hulls and the living area on one level between them. The saloon opens straight onto the cockpit, the side decks are wide and flat, and six adults can spend a week aboard without queueing for anything. A monohull of the same length has less room, and part of it sits down steps and below the waterline, where a Med summer makes it hot.
Sailing and comfort
- Heel. A catamaran barely leans. Plates stay on the table, children sleep through the passage, and the cook works standing up. A monohull heels 15 to 25 degrees under sail, which some owners enjoy.
- Upwind. A monohull points higher into the wind. A cruising catamaran is quick on a reach but loses ground upwind, so owners often start the engine for the last miles to a harbour.
- Short chop. Steep waves can slap the underside of the bridgedeck between the hulls. Ask the broker for the bridgedeck clearance of any catamaran you look at. More clearance means less slamming.
- Draft. Catamarans draw about 1.1 to 1.4 m on a 40 ft boat, so they get into shallower coves than a monohull with a 1.9 m keel.
The berth question
A 12 m catamaran is around 6.5 to 7 m wide. A 12 m monohull is about 4 m wide. Marinas charge for the area the boat occupies, and berths wide enough for a catamaran are scarce in busy ports. Call the marina before you make an offer and get the berth fee for the real beam. See Berths in Barcelona and the Med: wet berth, dry stack, renting vs buying a berth concession.
Purchase and running cost
A catamaran costs more than a monohull of the same length. It also has two engines, two saildrives or shafts, two sets of steering gear and often two of everything else. A haul-out for a catamaran needs a boatyard with a wide enough travel lift, which limits your choice of yard.
Who each suits
- A family or group that spends most nights at anchor: catamaran.
- A couple who want to sail well and keep the berth bill down: monohull.
- Unsure: charter both for a week each. See Try before you buy: chartering the model first.
If you buy a catamaran, read Catamaran-specific inspection points before the survey.
Related guides
General information, not legal, tax or financial advice. Rules change; check your own case with a professional or ask us.