What does an electric boat cost to run? Electricity vs petrol, maintenance and fees compared

An electric outboard in the 9.9 hp class costs around £1.18 of electricity per hour at full power in the UK, and a comparable petrol outboard around £6.79 of fuel. In Germany the figures are €1.62 and €8.45. That is our own calculation with official energy prices from October 2026 and manufacturer figures. On top of that, an electric motor needs no oil changes, spark plugs or impeller, and in the UK and some Dutch cities you pay lower fees.

What does an hour on the water cost with electricity and with petrol?

For a fair comparison you need two motors that the manufacturer itself puts on a par. Mercury compares its Avator 35e with a 9.9 hp four-stroke; at full power it draws 4.47 kW from the battery (Mercury brochure, Mercury). For the petrol engine, Yamaha states a consumption of 3.9 litres per hour at 5,500 rpm for the F9.9 (Yamaha Product Information Guide 2024). With official prices, our calculation gives:

Petrol sources: DESNZ (UK), EU Weekly Oil Bulletin (DE, AT, as of 26.10.2026), CBS (NL), BAZG/BFS (CH, September 2026). Electricity: Ofgem (UK), Eurostat (DE, AT, NL, first half of 2026), ElCom (CH, 2027 tariff).

Three caveats: Yamaha states consumption at 5,500 rpm, not explicitly at full throttle. We have not included charging losses or battery wear, because no manufacturer gives figures for them. And the UK electricity price excludes the standing charge; VAT on electricity has been removed from 1 October 2026 to 31 March 2027. Germany's Federal Statistical Office gives an average of 37.97 cents/kWh for households (Destatis), which barely changes the result.

At slow speed, power consumption drops sharply, often to a fraction. How much is shown in Electric boat motor range: how far can you go on one charge?. The Avator itself is covered in Mercury Avator and RAD Propulsion compared.

Which maintenance disappears with an electric motor?

An electric motor has no engine oil, no gear oil, no spark plug and no cooling water impeller. For petrol outboards, the manuals require exactly these regularly:

• Tohatsu MFS 6D: engine oil and gear oil after the first 20 hours, then every 100 hours or 6 months; check the spark plug at the same intervals; water pump impeller every 12 months (manual).
• Tohatsu MFS 9.9C: engine oil every 100 hours or 6 months, impeller replaced every 400 hours or 2 years by a dealer (manual).
• Suzuki: annual service at a dealer, water pump checked every year and replaced every 3 years (Suzuki).

Electric motors are not entirely maintenance-free either:

• Torqeedo Cruise: check the sacrificial anodes every 6 months or 100 hours, treat the contacts monthly with contact spray, rinse with fresh water after every trip. Every 5 years or 500 hours a service partner replaces the shaft seals. If you skip or do not document the intervals, you lose warranty and statutory guarantee (Torqeedo).
• ePropulsion Navy Evo: check anode and propeller yourself after 50 and 100 hours, at a dealer every 200 hours or 12 months; clean the contacts every two months (manual Navy 3.0 Evo).

None of the manufacturers states what a dealer service costs.

Do electric boats pay lower fees?

In some countries, yes; in Germany and Austria we found no such reduction:

• United Kingdom: on Environment Agency waters, boats powered solely by electricity pay 75% of the charge (Environment Agency). The Canal & River Trust gives a 25% discount when an electric motor is the only means of propulsion (CRT). More in Electric narrowboats: Ortomarine and Mothership.
• Netherlands, Utrecht: in the visitors' harbour a zero-emission boat up to 10 m pays €26.25 instead of €37.50 a day, and €6.45 instead of €9.20 at the lock (Gemeente Utrecht).
• Netherlands, Amsterdam: since 1 April 2026, harbour dues for leisure boats are 25% lower for zero-emission boats and for hybrids that run only on electricity in the city (Amsterdam regulation).
• Switzerland, canton of Lucerne: the government may reduce boat tax by up to 50% for particularly low-emission motors, but does not have to (boat tax act).

If you want to holiday on an electric boat in the Netherlands, hire companies are compared in Electric houseboat hire in the Netherlands.