The fourth Thames 21 Photography Competition is looking for original and beautiful photos of London's waterways.
A quick search of our Flickrpool throws up dozens of glorious shots of rivers and canals. As long as your shot hasn't already won a competition or been commended, you can enter it (in fact, enter up to three photos in total) and be in with a chance of winning a cash prize and the esteemed honour of being exhibited at National Maritime Museum in Greenwich.
The competition is open until 2 February which gives you plenty of time to get out and about and capture new, wintry images of the capital's waterways. There are also a number of Thames21 events that you can get involved with, which could supply ideal subject material, be it clean-up days, walks or conservation work, possibly in bits of London you've not visited before.
Check out the full competition terms and conditions online.