Six crews competing for a £100,000 prize set off from Tower Bridge on Saturday morning to try to beat the record for rowing non-stop round Great Britain.
Just after 8.15am the royal rowbarge Gloriana led the six competing boats under Tower Bridge to officially start the epic race.
Family and friends of the crews lined Tower Bridge to wave the crews off.
The six crews will row 2,000 miles non-stop and unassisted around the coast of mainland Britain.
The current record stands at 26 days, 21 hours and 14 minutes The first boat to break that record will win a £100,000 bounty.
• Follow the teams' progress at www.gbrowchallenge.com