Just months out of his "ER" surgical scrubs, George Clooney is donning fishing garb and sailing some rough seas. Clooney, one of PEOPLE's Sexiest Men Alive, began filming the movie version of author Sebastian Junger's "The Perfect Storm" Tuesday in Glouchester, Mass. The story details the last voyage of the Andrea Gail, a fishing boat that went down in a brutal storm in 1991. Mark Wahlberg and Mary Elizabeth Mastrantonio also star. Clooney told the Associated Press yesterday that the story is a poignant and important one. "They're real people," he said. "There are real families involved."