LONDON-Kate Winslet managed to hold her breath underwater for an impressive eight minutes at a time on the set of 'Avatar', according to producer Jon Landau. Kate Winslet held her breath underwater for eight minutes at a time on the set of 'Avatar'.

The 43-year-old actress plays Ronal, a free-diver of the Metkayina clan, in the hotly-anticipated sequels to the fantasy movies and producer Jon Landau was impressed with how quick she picked up the new skill.

Speaking at the IMAX Q&A for 'Alita: Battle Angel, he said: ''We built a water tank that was 500,000 gallons of water, and we are doing performance-capture under the water, on the surface of the water, and above the water. We trained our cast to free-breath-hold, because in the sequences they have to just be swimming, they can't be on scuba, and they have to be able to do long takes.

''So we had a gentleman named Kirk Krack come in and train everybody that needed to be underwater how to go underwater and how to hold their breath. Kate Winslet had to train in this and she got up to a static breath hold of just about seven minutes. It's amazing, it's mind over matter. You see Kate going underwater and she just felt so comfortable. There was one day, we have a tank where she was just rehearsing and testing and we have some windows into it, and I go in there and she's just walking on the bottom [of the tank] left and right, left and right, left and right, then she sees me in the window and she just waves. I couldn't believe it!''

Director James Cameron - who also worked with Kate on 1997's 'Titanic' was thrilled to welcome her on board.

He said at the time: ''Kate and I have been looking for something to do together for 20 years, since our collaboration on 'Titanic', which was one of the most rewarding of my career. I can't wait to see her bring the character of Ronal to life.''