The Darkness frontman Justin Hawkins swapped his catsuit for a wetsuit for his appearance on The Friday Night Project.
Hawkins is guest-presenting the Channel 4 show this week.
He was joined by regular hosts Alan Carr and Justin Lee Collins for a day out on the river.
The trio tried their hand at various water sports, including wake-boarding and banana-boating at the Princes Sporting Club in Bedfont, Middlesex.
A bedraggled Hawkins ended up in the drink.
Hawkins follows the likes of Mischa Barton and Jade Goody as a guest host.
The Friday Night Project is on Channel 4 tomorrow at 10.30pm.