You know you’re getting deep, says Loretta Hidalgo, when the clothesline begins to sag. More than two miles below the surface of the ocean, the water pressure is so intense it could crush a submersible like a soda can. Fortunately, the Soyuz-like capsule in which Hidalgo and a colleague were riding recently was built to withstand the severe conditions. Even so, at 3,500 meters the section of cord stretched taut across the interior of the craft was taut no more. “Literally, the walls were caving in,” she says.

Hidalgo, ’96, was one of a handful of scientists chosen by director James Cameron (Titanic, Aliens) to record the exotic menagerie near hydrothermal vents at the bottom of the ocean for an upcoming IMAX film. She and Kevin Hand, a Stanford PhD student in geology, dove several times from the Russian boat Academic Keldysh, the largest research vessel in the world, in Atlantic locations stretching from the Azores to the Caribbean. On the deepest dive, which required a 2 1⁄2-hour descent, they observed what looked like “a fire hose spewing black smoke,” Hidalgo says. The hot (400 degrees or more), mineral-rich effluence produces an environment “teeming with life” and eventually hardens into material pillars 40 feet tall.

Trained in biology and astrobiology, Hidalgo is president of the nonprofit Space Exploration Foundation. What does space study have to do with a research project on the ocean floor? “In the movie we talked about the extreme life forms that live there and what they may mean for scientists looking for life elsewhere in the galaxy,” she says.

Hidalgo admits that despite the stunning display down deep, thoughts of safety were ever-present. “You just hope the guys who built [the submersible] did a good job. Your life is in their bolts.”

The film, Extreme Life, is scheduled for release early in 2005.