Water is the constraint nobody mentions in the brochure. Diesel you can buy at a fuel berth. Food you can buy at any market. But the moment you anchor off an island for three days, the fresh water you carry is all you have, and a tank runs out faster than a confident skipper expects. I have rationed water badly twice and well ever since. This is what I have learned about living within a tank in France.
Know your number
Start with the only figure that matters: how many litres your tank actually holds, not what the brochure claimed. A typical 32 to 36 foot cruising yacht carries somewhere between 150 and 300 litres, often in a single tank under a settee or the cabin sole. A 36-footer commonly has around 300 litres. That sounds generous until you divide it by mouths.
Consumption is where crews fool themselves. Live aboard as you would at home, long showers and free-running taps, and you will get through 75 to 150 litres per person per day, which empties any cruising tank in a single morning. The old long-passage discipline of 10 litres per person per day is hard to keep close to the coast, but careful cruisers manage 15 to 25 litres a head with a bit of thought, and the most disciplined long-distance sailors get down to 3 to 5 litres a head with real effort. At 20 litres each, a 200 litre tank gives two people five days and a crew of six under two. Do that sum before you leave the dock.
It helps to know where the water actually goes, because it is not where people assume. Drinking and cooking is the smallest slice, a few litres a head. Washing up is more, especially if you rinse under a running tap. And showers are the runaway cost: a single freshwater shower on a pressurised system can swallow 20 or 30 litres on its own, which is to say one person's whole daily ration in five minutes. Identify your big spenders and you know where to find the savings, and almost always the answer is the shower and the running tap.
Where to fill in France
The reliable fill is a marina. Almost every French marina has potable water on the visitor pontoons, usually a tap shared between berths, and on most you fill as part of the nightly berth fee with no separate water charge. A few meter it or use a token, the jeton, from the capitainerie. France charges municipal water at roughly 4 to 5 euros per cubic metre at the household level, so even where a marina passes the cost on, filling a 200 litre tank is small money. The cost that bites is the berth, not the water.
Practical fill tips that save grief:
- Carry a long hose, at least 15 metres, and a fistful of tap adaptors, because French pontoon taps come in shapes your hose has never met.
- Taste before you trust. Most French marina water is potable and fine, but some tastes of the hose or the dock. A carbon filter on the inlet helps.
- Fill at the marina the night before a long anchorage leg, not after, so you leave with a full tank.
Anchorages rarely offer water. A dinghy run ashore with collapsible jerry cans to a town tap or a marina is the fallback, and it is a chore, which is the whole argument for not running dry in the first place. A collapsible 20 litre jerry can stows flat and weighs nothing empty, and two of them mean you can lug 40 litres back from a town tap if you have to. That is two days for a couple, but it is a wet, awkward dinghy trip you will resent, so I treat the jerry cans as the emergency option, not the plan.
One quiet trap on the French Atlantic and Channel coasts is the tidal harbour that dries. You may arrive, take the ground, and find the water tap is on a pontoon that is now high and dry or a long muddy walk away. Check how you will reach the tap before you commit, especially in Brittany and Normandy where the tidal range is large and a marina that floats at high water is a different place six hours later.
Stretching a tank
The difference between a tank that lasts and one that does not is a handful of habits, none of them hardship once they are routine.
Seawater does half the work. The first wash of dirty pans, the rinse of muddy anchor gear, the cooling dip instead of a shower: all seawater, all free, all saving the tank for what only fresh water can do. A bucket on a lanyard is the cheapest water-saving kit on the boat.
Showers are the great drain. A marina shower ashore, often included or a euro or two in the fee, takes the whole load off your tank. At anchor a sun shower bag warms a few litres on deck and a disciplined rinse uses a fraction of what a pumped shower does. The foot pump beats a pressurised tap every time, because you stop the flow the instant your hands leave it.
Drinking water is the line I never cross. I keep at least a dozen 1.5 litre bottles of supermarket mineral water aboard, around 18 litres, both as drinking stock and as the reserve that means a fouled or empty tank is an inconvenience, not an emergency. Supermarket still water costs well under a euro for a six-pack of 1.5 litre bottles, so this is cheap insurance, not a luxury. Stocking those bottles is part of the same job as the wine and beer, which I cover in drinks locker france.
A few more habits that add up faster than any single one:
- Catch the tap water in a basin to wash up, rather than running it, and you use a litre where a running tap would use ten.
- Rinse salt off skin and gear at the marina before you leave, on their water, not yours.
- Fix the dripping tap or the weeping connector before the cruise, because a slow leak empties a tank invisibly over a week.
- Keep the tank topped rather than running it down to a quarter, so a missed fill is never a crisis.
The watermaker question
For long-range cruising, or for crews who refuse to ration, a watermaker turns the sea into the tank and removes the whole problem. It also costs money, draws power and needs servicing, so it suits some boats and not others. Whether it is worth it for French coastal cruising, where marinas are frequent and fills are cheap, is a genuine question rather than an obvious yes, and I weigh it up in watermaker french cruising. My own view, for hopping along the French coast, is that a bigger tank and good discipline beat the complexity. For a Biscay crossing or weeks at remote anchor, the answer changes.
Plan it like a passage
Water deserves the same planning as the route. Before each leg I ask three questions: how full is the tank, how many days and mouths until the next certain fill, and what is the fallback if that fill fails. If the answer to the second is more than the answer to the first can cover, I top up before I go or I shorten the leg. A full crew makes this acute, which is why feeding and watering a big crew are really the same problem, worked through in feeding crew of six.
The skippers who run dry are not unlucky. They simply never did the arithmetic, trusted a tank gauge that lies, and assumed water would appear because it always had ashore. On a boat it does not appear. You carry it, you ration it, and you fill it before you need it. Get that right and water stops being the thing that cuts a good cruise short.
