@bjw has challenged me to "Base a photo on contrasting or complementing colours".
Our beautiful beach - often deserted http://365project.org/jocasta/365/2013-06-02
- has been invaded by power boats and jet skis. The only plus side is that great big, colourful tractors are used to bring the boats to the beach.
I would say this meets your challenge perfectly. Great colour contrasts here and super composition too Jocasta. Pity about all those noisy types invading your lovely beach!