The Environment Agency (EA) issues guidance on river conditions on the Thames, which are updated once a day by 11:00.
The warnings for the stretch of the river between Shepperton and Molesey locks were “red caution: strong stream” on Friday.
According to the agency, when red boards are displayed at the locks, users of all boats are advised not to navigate.
“The strong flows make it difficult and dangerous,” the guidance says.
An EA spokesperson said in general, and unconnected to Friday’s incident, that boat-owners should check river conditions, whether on boats or not.
