A French marina berth is expensive and, for a non-resident owner, often empty for months. The obvious thought is to rent it out while you are home, recover some of the cost, and keep the slot warm. The obvious thought is also, in most French ports, against the rules. Before you advertise your berth to a passing cruiser, understand what you can and cannot legally do, because the penalty for getting it wrong is losing the berth entirely.
I looked into this seriously when my own boat was going to sit unused for a long winter, and the answer turned out to be more nuanced than a flat no.
The default rule: you cannot sublet
In a standard French marina, your berth contract gives you the right to keep your boat there. It does not give you the right to rent the space to someone else. Subletting (sous-location) is prohibited under most port byelaws, and that prohibition is written into the contract you signed with the capitainerie. The berth is allocated to you and your boat, not as a tradeable commodity.
The reasoning is straightforward from the port's side. The capitainerie wants control over who occupies its water, for safety, insurance and revenue reasons. When your berth sits empty, the harbourmaster wants to be the one renting it to visitors at the nightly visitor rate, and pocketing that income, not you. So the default position across French ports is simple: you may not sublet your berth to another boat owner.
The exception: amodiation
There is one genuine legal route to leasing out a berth, and it is the amodiation. An amodiation is a long-term contractual arrangement, a sort of farm-out, between the port and an individual, giving that individual the use of a specific berth for a fixed long term, sometimes decades. Where this exists, the holder of the amodiation can legally rent the berth to another individual for all or part of the period.
Amodiations are not the norm and they are not handed out casually. They exist in particular ports, often were sold years ago, and they trade at a premium because they are one of the few ways to secure berthing on a tight coast. If you hold one, you have rights an ordinary annual contract holder does not, including the right to sublet within the terms the port set. If you do not, the amodiation route is not something you can simply opt into for a single empty winter. Whether a long-stay berth in your port can be held this way is part of the broader question covered in the guide to a permanent long-stay berth in France for a foreigner.
The legal middle ground: the absence rebate
Here is the arrangement that actually helps most foreign owners, and it is fully sanctioned: tell the harbourmaster when you will be away.
Most French ports have a system for declared absences. When you notify the capitainerie of a planned and prolonged absence, with the dates, they are free to use your empty berth for visiting boats during that window, and in exchange many ports give you a rebate or credit against your fees. The port earns the visitor income, you get a discount, and everyone is inside the rules. Some ports build this into the contract explicitly, with specific benefits for owners who free up a berth during the peak season when visitor demand is highest.
The catch is that you must declare it. A berth you simply abandon for the winter without telling anyone earns you nothing, and in some ports an undeclared long absence lets the harbourmaster reallocate the space at their discretion anyway. So the move is not to quietly sublet, it is to formally hand the empty berth back to the port for the period and take the rebate. Ask your capitainerie exactly how their absence scheme works, because the terms vary port to port.
What renting out actually costs you in risk
Weigh the upside against what you stand to lose.
If you sublet against your contract and the port finds out, the realistic consequence is termination of your berth agreement. On a coast where the best regions to base a boat all have waiting lists running into years, losing a hard-won berth to claw back a few hundred euros is a catastrophic trade. There is also the insurance problem: if another owner's boat is in your berth under an informal private deal and something goes wrong, a collision, a sinking, a fire, the liability picture is a mess, and your insurer may decline because the arrangement breached the port rules.
For the modest sums involved, the informal sublet is rarely worth the exposure. The declared-absence rebate gets you most of the financial benefit with none of the risk.
How the absence scheme works in practice
The mechanics vary, but the pattern across ports I have dealt with is consistent enough to plan around.
You notify the capitainerie in writing, ideally by email so there is a record, giving the date your boat leaves and a firm or estimated return date. The longer and more certain the absence, the better the deal, because the port can confidently sell your berth to visitors for that whole stretch. Some ports want a minimum absence, often a few weeks, before any rebate kicks in. The credit is usually calculated against the nights the berth was genuinely available, and it may appear as a discount on next year's contract rather than a cash refund.
Two practical points. First, leave the port a way to reach you, a phone number and email that work from abroad, so that if your dates change they can adjust rather than assume you have abandoned the berth. Second, if you are leaving the boat itself in the water elsewhere or hauled out for the winter, the winter haul-out and yard arrangements need booking at the same time, because the berth absence and the yard slot are two halves of the same plan.
Renting the boat, not the berth
One thing foreign owners sometimes conflate: renting out your berth and renting out your boat are different questions with different rules. Chartering your own boat to others, through a peer-to-peer platform or otherwise, brings its own regulatory and insurance requirements, commercial-use coding, the right insurance cover, and tax considerations, and doing it commercially can change the legal status of both boat and berth. That is a separate decision from the berth question, and if it tempts you, treat it as a proper commercial undertaking rather than a casual side income.
The sensible play for a non-resident owner
If your boat sits empty for long stretches, do this. Read your port byelaws and your berth contract for the exact wording on sous-location and absences. Assume subletting is forbidden unless you hold an amodiation that says otherwise. When you know you will be away for weeks or months, declare the absence to the capitainerie in writing, with dates, and ask for the rebate or credit they offer in return. Keep that agreement on file.
That route is legal, low-effort, and it shaves real money off a berth that would otherwise sit dead. It will not turn your berth into an income stream, but a French marina berth was never going to be one. The win is keeping the slot, staying on good terms with the harbourmaster, and not handing a lawyer a reason to take your berth away. When the day comes that you do want out for good, the clean record you have kept feeds straight into a smooth boat sale through a French broker.
