Vet helmer Hall uses 'rebreather' to make big-screen pic

Veteran undersea director Howard Hall has pioneered several technological breakthroughs in underwater large-format filmmaking for “Island of the Sharks,” an Imax film produced by Nova/WGBH Boston with Howard Hall Prods. and the New England Aquarium.

Filming off Cocos Island, Costa Rica, Hall and his crew used an underwater breathing system, developed by the military, which allows extended dives of up to 12 hours. The system doesn’t generate bubbles and is silent, making it ideal for filming marine life. Hall’s use of the so-called rebreather on a previous project made him the first filmmaker to ever use the system.

In all, Hall and “Sharks” cameraman Bob Cranston spent roughly 1,300 hours underwater on six filming expeditions for the pic.

“Sharks,” Nova’s fourth giant-screen film, is set to premiere in April. Other upcoming giant-screen films for Nova include “Volcano: Lost City of Pompeii” and “Invisible Worlds.”

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