Celebrity magician DAVID BLAINE started his new stunt of spending seven days underwater in a human aquarium in New York City yesterday (01MAY06). The 33-year-old illusionist will be held in a 2.5 metre (eight feet) wide sphere filled with water and will survive using just a breathing mask and a feeding tube. The stuntman plans to end his superhuman feat by breaking the world record for holding breath underwater - which currently stands at eight minutes and fifty-eight seconds. Blaine will be handcuffed to 150 pound (68 kilogram) metal chains from which he has to escape after holding his breath. He says, "So basically besides holding my breath for about nine minutes hopefully I will have to escape from all these chains, and if not I will drown and the world will see something pretty insane." DR MOURAT GUNEL, a specialist in the surgical treatment of strokes, has warned Blaine the stunt carries a risk of irreversible brain damage: "David might never be the same again. Even if he is fine immediately after, there is a risk for developing seizures in the long run. "We all advised him against this stunt." But Blaine insists, "My only fear is the unknown."