Have a look at these stunning pictures, winners and runners-up in a competition by the British Society of Underwater Photographers.
This grey seal certainly isn't camera shy! It was snapped on Lundy Island, in the Bristol Channel.
These stunning pictures are winners and runners-up in a competition by the British Society of Underwater Photographers. This is a sea creature called a fireworks anemone, which was snapped in Loch Duich in Scotland.
This creature doesn't look as pleased to see us! It's a Yarrell's blenny - check out its little tentacles on its head!
This photo of a blue shark was taken out in the Atlantic Ocean.
Can you work out what this is? It's a porcelain crab and was taken in Indonesia.
This colourful photo of a clownfish was taken in the Maldives. It looks like it has dreadlocks but it's actually surrounded by a sea creature called an anemone.
This jellyfish against a sunburst was captured on Lundy Island.