Speedboat racing on the River Thames near Chiswick.
Full title reads: "Chiswick. Hydroplanes of all Nations. Compete for Thames International Championship Challenge Trophy - R D Weatherell won in 'Fish XVII'."
Shots of hydroplanes / small speed boats racing on River Thames. The boats travel very fast.
Shots of a capsized boat. The driver hangs on to a rope on the boat. A launch comes out to pick him up.
More shots of race.