We swapped a monohull for a 12 m cruising cat the winter before our first French season, and the question I had then is the one I get asked most now: is a catamaran better or worse for cruising France? The honest answer is both, and which one wins depends entirely on where you point the bows. France is a country of two completely different cruising grounds, and the catamaran is brilliant in one of them and awkward in the other.
The case for the cat on the Atlantic
If your season is the Atlantic coast and Brittany, the multihull earns its keep on day one. The thing that makes this coast hard for deep-keeled boats is the tide and the drying ground, and a cruising cat draws far less than the equivalent monohull. Our boat sits at about 1.2 m, where a 40 ft cruising monohull is usually 1.9 to 2.1 m. That 800 mm is the difference between sitting upright on a sandbank for lunch and not being able to get into half the anchorages on the Atlantic side.
Take the Bassin d'Arcachon. The entry channel shifts every season and the lagoon dries over vast areas at low water, so the shallow draught of a multihull lets you tuck behind the Banc d'Arguin where the keelboats cannot follow. I have written up the full picture of getting in and around there in the Arcachon basin sailing guide, and it is a textbook case of a place built for a shoal-draught boat.
The same logic runs up the whole seaboard. A boat that can take the ground and float in a metre opens up the drying harbours, the river anchorages and the back-of-the-bay spots that a fin-keeler reaches only at half tide. If you want the detail on which boats this suits and where, the shoal draught France Atlantic coast guide goes through it port by port.
Drying out: the cat does it without trying
Here is the trick that turns Brittany sailors green. A catamaran does not need legs, a wall to lean against, or twin bilge keels to dry out. It sits flat on its two hulls, level, with the kettle on. We have spent whole tides parked on hard sand in the Golfe du Morbihan while monohull crews fussed with drying lines against a quay.
That said, do not get cocky. You still want to dry on clean, even sand, not on a rocky scour or a mooring chain you cannot see. The technique and the harbours where it works are the same ones the bilge-keel crowd use, and the bilge keel France drying-harbours piece covers the choice of ground in detail. A cat just gets there with less ceremony.
Where the beam starts to hurt
Now the bad news, and it is all about width. A 40 ft cruising cat is commonly 6.5 to 7.5 m wide. A 40 ft monohull is around 4 m. That extra three metres of beam follows you into every marina, and France charges for it.
French visitor berths are priced on length overall, but multihulls almost always pay a surcharge, and the standard one is 50 percent on top of the monohull rate. So if a 12 m monohull pays a peak-season rate of, say, 45 to 55 euros a night in a busy Brittany or Atlantic marina, your cat pays that plus half again. On the Cote d'Azur in August the base rates are far higher to begin with, and the multihull surcharge stacks on top, so a high-season night for a big cat in a fashionable Riviera port can run well into three figures. I keep an eye on the going rates in the French marina cost per night breakdown, and the multihull premium is the single biggest line-item difference between us and our monohull friends.
Beam also costs you berths outright. Plenty of older French marinas were laid out for monohulls and simply do not have catamaran-width finger berths. Phone ahead. The capitainerie will often raft you, put you on a hammerhead, or turn you away on a busy weekend, and "we are full for multihulls" is a sentence you will hear. Book early, especially in August.
The numbers that decide the canals
If your plan is to cross France inland, the catamaran question gets brutal and the answer is usually no. The French canal network runs to the Freycinet gauge, and the figure that kills it is the lock width. Standard Freycinet locks are about 5.0 to 5.05 m wide, length around 38.5 m, with a working draught limit near 1.8 m and an air-draft ceiling around 3.5 m.
A monohull at 4 m beam slides into a 5 m lock. A 6.5 to 7.5 m catamaran does not fit, full stop. There are wider gauges on parts of the Rhone, the Saone and the big northern canals that take commercial barges, but the classic cross-France routes such as the Canal du Midi and the Canal de Bourgogne are pure Freycinet and they are closed to you. Before anyone tells you it can be done, check your beam against the Freycinet gauge canal dimensions, because this is the one number you cannot argue with. A cruising cat going from the Channel to the Med goes round Biscay and through Gibraltar, not through the middle of France.
Anchoring, posidonia and the Med
On the Mediterranean the calculus flips again. The catamaran's shallow draught lets you anchor closer in and in thinner water, which is genuinely useful on a crowded Riviera summer night. But the same authorities have cracked down hard on anchoring over posidonia seagrass, with no-anchor zones, fixed eco-moorings and fines that have run into four figures for dropping the hook on protected meadows. A cat's light draught does not exempt you from that, so you still read the zones and pick sand. The flat, stable platform is a real pleasure at anchor in a Med swell, where a monohull rolls and the cat barely notices, and that comfort is the multihull's clearest win in the south.
The practical day-to-day differences
Beyond the big strategic questions there are a dozen small ways the catamaran changes daily life on the French coast, and they add up over a season. Provisioning is easier, because the flat deck and the wide cockpit swallow a fortnight of supplies and the dinghy lives on davits across the stern rather than on the foredeck. Getting children and non-sailors aboard from a pontoon is a step across, not a clamber down, which matters more than you would think when the whole family is sailing.
Manoeuvring in a tight French marina is the flip side. Twin engines set well apart make a cat turn in its own length, which is a gift when a capitainerie sends you down a narrow fairway to a hammerhead. But the same beam that the engines control so neatly is the beam the berth has to accommodate, so the boat that handles best in the marina is also the one most likely to be told there is no room. You learn to phone ahead, give your length and beam together, and accept a raft or an end berth without complaint.
Fuel and water tankage tends to be generous on a cruising cat, spread across two hulls, which suits the Atlantic where fuel berths are not on every quay. That extra range pairs well with the shallow draught for poking into the back-bay anchorages, and it means you bunker on your schedule rather than the marina's.
So which is it, better or worse?
For an Atlantic and Brittany season, I would take the cat every time. The shallow draught, the ability to dry flat, and the deck space for a family outweigh the berth surcharge, and the cruising ground is built for it. For a canal crossing it is a non-starter, and you should not even price it. For the Med it is a comfort upgrade with a cost penalty, and you live with the August berthing scramble.
The mistake I see is people buying the boat for the brochure and not the ground. If you have already chosen the cat, point it at the Atlantic and the islands and you will spend the season smug. If you are still choosing, match the boat to the coast first and the marketing second. A boat that fits where you actually want to sail beats a boat that looks good on a pontoon you cannot get into.
