Underwater photography competition winners - in pictures

First place: Trevor Rees - Nudibranch (Flabellina lineata). The sea slug, or nudibranch, Flabellina lineata, has delicate tentacles with white tips. It is widespread around much of the UK coastline. As well as being enchanted by the subject, judges were impressed by the technical skill involved in capturing a quality close up of such a small species underwater. Trevor said: 'Flabellina lineata is a great example of how attractive an underwater slug can be compared to a land slug. My image was taken in Loch Creran on Scotland's west coast in about six metres of water. During the dive there were a lot of these creatures feeding in the rich current swept waters of the loch. They were present on rocks and weed with this one found on kelp. A low angle enabled me to get a striking head on portrait using a housed SLR camera with a macro lens' Photograph: Trevor Rees/2011 BSoUP

Second place: Robert Bailey - Yarrell's blenny, Loch Long, Scotland. This fish has bushy tentacles and is uncommon around the UK’s coastline. Judges were delighted to see such a beautiful portrait of one. Robert said: 'The picture was taken in Loch Long in Scotland in late spring. The image was taken in fairly shallow water – less than 10 metres. The blenny was sitting on the bottom and was comfortable with my approach. It stayed long enough to allow me three shots. I used a 60mm macro lens with a Nikon D300 and Sea & Sea housing, and one Inon Z240 strobe with a snoot on the light' Photograph: Robert Bailey/2011 BSoUP

Third place: Dan Bolt – Kelp, Lundy Island, Devon. Joan Edwards, head of living seas for the Wildlife Trusts, said: 'Each year, the BSoUP competition entries demonstrate just how spectacular the wildlife living in our seas is. It can be easy to dismiss the UK’s seas as dull and grey – but images like Trevor’s sea slug illustrate how much beauty is there to be discovered if you take a closer look. From the far north to the south-west, there are thriving habitats to be explored' Photograph: Dan Bolt/2011 BSoUP

Fourth place: Samantha Muir - John Dory, James Eagan Lane, Plymouth Photograph: Samantha Muir/2011 BSoUP

Fifth place: George Stoyle - Nudibranch (Polycera quadrilineata), North Rona, Scotland Photograph: George Stoyle/2011 BSoUP

Sixth place: Saeed Rashid - Seal in kelp, Farne Islands Photograph: Saeed Rashid/2011 BSoUP