Skippers have been warned to take extra care to avoid running aground this summer, after breakdown and emergency recovery firm River Canal Rescue (RCR) reported an 800% rise in groundings.

The company normally responds to one grounding callout per month, but since the beginning of June that level has risen eight-fold to an average of two per week.

This rise has been put down to lower water levels caused by the unusually hot weather over the past two months.

RCR adds that boats on the Thames, the Fens and “rivers in general” are particularly at risk.

Stephanie Horton, managing director of RCR, said: “The heat wave in June and July affected the water levels, creating a peak of call-outs at the end of July.

“To reduce the risk of grounding, keep to the deeper channels, do not cut corners and only travel where there is adequate water.”

Despite the recent heavy rainfall during Hurricane Bertha, Britain is on course for its eighth-warmest summer on record, with July seeing an average day-and-night temperature of 16.3C.