Kate Bush has apparently spent three days in a flotation tank to film footage for her upcoming live shows.

The 55-year-old singer, who is making her stage comeback after 35 years with a 22-night residency at London's Hammersmith Apollo, is including a scene in her show where she is lost at sea.

The Daily Mirror reported that earlier this month she hired an underwater stage at Pinewood Studios in Buckinghamshire and spent three days submerged in the water so the scenes could be shot.

A source said: "Kate wants the show to be out of this world and hired the underwater stage which is fitted with a wave machine and special lighting at Pinewood Studios.

"She spent three days in the tank re-shooting scenes and performing her songs. She wanted to create the effect of her floating in the ocean, lost at sea.

"The footage ends with her singing Hello Earth and being saved by a helicopter."

Kate effectively retired from touring after just six weeks on the road in 1979, and later revealed that her years of absence from the touring circuit were simply down to the sheer exertion of the ordeal.

In March she announced she was returning with Before The Dawn and released a poster of herself wearing a life jacket in the sea.

Kate, whose shows sold out in less than 15 minutes, takes to the stage at the Hammersmith Apollo in August.