This coming Saturday is one of the great annual events of the Thames - The Great River Race.
A river marathon for rowers, it is a race over 22 miles of the Thames through central London, usually from Richmond to Docklands.
There can be up to 300 entries, from traditional skiffs to ocean crossing craft to dragon boats, thousands of competitors on the river.
It is also a reminder of the history of the Thames as a working river, and the centuries in which the Company of Watermen & Lightermen was responsible for not just carrying passenger and cargos, but also training the next generation as apprentices. So each entry must carry at least one passenger.
And this year they are doing it backwards! Because of the tides it will be starting in Docklands and heading up river rather than the other way round.
If you are in London look out for it, as it should be a great spectacle: the video above gives a feel to what it looked like last year.
Update: it looks like there will be wind against tide conditions for the race - could get a bit bumpy out there!