How to use it
Engine hours are the hours on the move. The cruise time planner gives you that from the miles and locks. Then type how many litres an hour your engine burns, how many people are aboard, for how many days, and the size of your water tank. Add a price a litre if you want a cost.
How it is worked out
It is plain multiplying. Diesel is engine hours times litres an hour. Water is people times days times litres each a day. Then the water is shared out by the size of your tank to show how many fills you need.
About the starting figures
The boxes start at 1.5 litres of diesel an hour, 30 litres of water a person a day and a 500 litre tank. These are our own starting guesses, not measured and not from any published source. Engines, boats and crews differ a lot, so change them to your own.
Your best figures are your own. A fuel log tells you litres an hour: note the litres each time you fill up and the engine hours since the last fill. A hire boat's handover notes may say what it uses. The tank size is in the boat's paperwork.
Why it matters
The Canal & River Trust's Boater's Handbook puts it simply in its list before setting off: make sure you've got enough water and fuel on board for your trip. Water points and fuel boats are not on every stretch, so plan where you'll fill up.
Sources
Canal & River Trust, The Boater's Handbook (revision Spring 2022), page 6, read on 30 October 2026. The starting figures are ours, as above.