A boat's annual budget: the 10% rule explained

The 10% rule says a boat costs roughly 10% of its value every year to run: berth, insurance, maintenance, wintering and consumables. In practice the range runs from 8% for a simple sailing yacht maintained by her owner to 15% and beyond for a motor yacht handed entirely to a boatyard. A €200,000 boat therefore costs €16,000 to €30,000 a year, before you even cast off.

Where the 10% rule comes from

It is an empirical rule passed around by brokers and owners — not a law of physics. It works best for boats of 30 to 50 feet kept in Europe, which form the heart of the market. Below that, a trailerable RIB drops far under 10%: no berth, minimal upkeep, winter storage in the garden. Above it, the curve takes off: a crewed yacht carries 10% of a value counted in millions, and the percentage climbs further with payroll. The rule's value is not its precision but its effect: it forces you to think in total annual cost before buying, instead of stopping at the asking price on the listing. Brokers use it as a sanity check when qualifying buyers, and insurers and finance houses reason in very similar bands.

Line by line: where the money goes

For a 40-foot boat worth €150,000, here are realistic European ranges:

• Annual berth: €3,000-6,000 in the Mediterranean, €1,500-3,000 on Atlantic or Channel coasts — see our berth guide for detail.
• Insurance: 0.8-1.5% of the insured value, so €1,200-2,200.
• Haul-out and antifouling: €800-2,000 a year, lift included.
• Engine and mechanical upkeep: €500-1,500 depending on how much you delegate.
• Sails, rigging and deck hardware on a sailing yacht: €500-1,000 averaged over several years.
• Consumables, fuel, chandlery: €500-1,500 depending on use.
• Contingency: add 10-20% of the total, because something always comes up.

Total: €8,000-14,000 a year, or 5-9% of value — and more if a yard does everything. On a motor yacht used hard, fuel alone can double the bill. These figures also assume a boat in sound condition: a neglected one starts with a maintenance backlog that has to be paid off first.

What moves the bill

Size first, and it is not linear: six more feet often means 30-40% more cost, because everything scales — the marina's price band, sail area, engine power, litres of antifouling. Then propulsion: a cruiser running at 20 knots burns 60-100 litres an hour, where a sailing yacht sips almost nothing. Region matters: the French Riviera can double the berth line compared with Brittany or Britain's quieter harbours. Age, finally: value falls, but upkeep tracks size and complexity — as a percentage of market value, a fifteen-year-old boat often costs more than a new one. The most effective lever is your own labour: doing oil changes, antifouling and routine jobs yourself cuts the bill by 30-40% — see what you can realistically do yourself.

The costs everyone forgets

The running budget is not the whole story, and three blind spots come up again and again. Depreciation first: it is not an invoice, but it is a real loss of 3-8% a year depending on age and market. Then the ten-year items: a suit of sails (€8,000-20,000 for a 40-footer, every eight to twelve years), standing rigging (€5,000-10,000 every ten to fifteen years, often demanded by insurers), ageing electronics, upholstery, and a battery bank every five to seven years. Finally the periodic obligations: liferaft servicing every three years, extinguishers, and annual registration dues depending on your flag. The fix is simple: set aside 1-2% of the boat's value every year in a dedicated account, and these "surprises" become ordinary budget lines. None of them will catch a well-organised owner off guard; every one of them wrecks the budget of an unprepared one.

Where to start

Build your budget in half an hour, in this order:

• Estimate the boat's real current value — yours or the one you are eyeing — not its price five years ago.
• Get a written berth quote and an insurance quote: they are the two most predictable lines.
• Run every line through our cost of ownership calculator, which applies these ranges to your case.
• Add a 15% margin, then compare the result with your actual annual leisure budget.

If the total makes you wince, go smaller rather than rarer: a smaller boat that goes out thirty times a year beats a big one asleep at the dock. And to place your project in the wider picture, from RIB to superyacht, read what a yacht really costs.