Counting the hours

Although Chris Clegg is giving up boating after more than 60 years, his legacy is a single-sheet map that taught generations of boaters to measure the waterways not in miles but in time

After more than six decades afloat, Chris Clegg’s time on the inland waterways has come to an end. At 79, the physical effort has become harder, the costs more difficult to justify, and the waterways themselves, he feels, more crowded and slower than he remembers from his first trip in 1958. Nevertheless, Chris has ensured that he has left his mark on our inland boating scene. Even if you do not know him personally, there is a good chance that you are familiar with his work.

For more than 40 years, boaters have been planning their journeys using what has become affectionately known as “the Cleggy” – a single-sheet canal map that does not measure distance in miles, but in time. Instead of locks, pounds and junctions being plotted geographically, the network is redrawn as a sequence of evenly spaced points, each representing a fixed amount of cruising time. On one side of the A4 sheet are around 500 named places at two-hour intervals.

“You just count along the places on your route,” Chris says, “counting two, four, six, etc, as you go, and that gives the time in hours the route will take.”

On the other side of the sheet are summary maps at six, eight and ten hours, all designed to give a quick sense of how many days a longer route might take.

A simple concept, perhaps, but one that has proved hugely popular, for Chris estimates he has sold some 3,600 copies to date, mostly through the Inland Waterways Association website.

An idea born of frustration

Long before apps, route-planners or detailed guidebooks, calculating the duration of a journey was a laborious business.

“We used to work out how long a route would take by adding up the miles, and guessing what speed we would go, and adding up the locks, and guessing how long each one would take, and then combining the two,” Chris recalls. “Our first canal holiday was in 1958 when I was 11, and there wasn’t much in the form of guidebooks to look up the miles. The process was very tedious and based on guesswork to a large extent.” However, when his family acquired their first boat in 1965, Chris decided to get more involved in the journey-planning aspect. “It was clear that an easier way of doing it was needed,” he says.

The first version of the map appeared in around 1970, showing places a full day’s cruising apart, based on an eight-hour day underway. A commercially available version followed around a decade later. Over time, the format became more refined, with Chris eventually arriving at the two-hour interval map that most users now recognise.

This is an extract from an article that appears in Waterways World May 2026