BEVERLY HILLS, California: The hardest thing about a pirate's life for Penelope Cruz was not all the swashbuckling and sword fighting and sailing the high seas. It was not even the added rigor of being a pregnant pirate as she filmed her scenes last summer for “Pirates of the Caribbean: On Stranger Tides” while carrying her first child. Cruz said her toughest job on the fourth “Pirates” flick was staying in character opposite Johnny Depp as woozy buccaneer Jack Sparrow. “To keep a straight face sometimes with Johnny in some of the more dramatic scenes,” Cruz said in an interview for “On Stranger Tides”. Cruz, 37, was easy pickings for Depp, Marshall and the rest of the “Pirates” crew, who landed her without having to put out much bait. She had been friends with Depp since they co-starred in 2001's crime drama “Blow”. A fan of the original “Pirates” trilogy, Cruz said the decision to enlist took no thought at all. She plays Angelica, Sparrow's embittered former lover, the daughter of dread pirate Blackbeard (Ian McShane).