Javier Bardem has dived to the bottom of the Antarctic Ocean in a two-person submarine in support of a campaign to create an Antarctic Ocean Sanctuary.

The 'Skyfall' star described the experience as ''overwhelming'' but also surprisingly ''relaxed''.

Javier, 48, joined Greenpeace marine biologist John Hocevar - who piloted the submarine - on a two-hour expedition to the Antarctic Peninsula seabed, 270 metres below the surface.

The 'No Country for Old Men' star - who is married to Penelope Cruz - revealed: ''As soon as we reached the seafloor, I was completely amazed by the overwhelming variety of colours and life all around us. I'm not a biologist, but to find a pink, yellow and green world of corals and sponges at the bottom of the Antarctic Ocean was a real surprise to me.''

He added: ''It was a very relaxed experience, even though I'd expected to become more nervous, as we dived into the deep.

''It is really impressive to witness the scientific research that is done on this expedition first-hand and I'm just very grateful to be allowed one dive in between the many others where a real Antarctic biologist is in the passenger seat!''

Greenpeace is currently embarking on a three-month expedition to the Antarctic researching environmental effects such as plastic pollution, to highlight the need to create a 1.8 million square kilometre Antarctic Ocean Sanctuary, in order to safeguard species like whales and penguins.

Oscar-winning actor Javier said: ''To me, an experience like this shows exactly why we need to show respect as human beings. It is an incredibly important mission to go down and document these species in all their colourful existence to prove the importance of protecting a unique ocean that also feeds all the bigger animals in the Antarctic''.

John revealed: ''Being in a two-person submarine with Javier Bardem was awesome. He was a very relaxed passenger, especially considering this was his first dive. He seemed completely awestruck by the whole experience and so was I.''