A passenger wearing a life jacket prepares to take a picture of a whale very close to the boat.
A man is using a camera.
Man is a passenger, and prepares to take a picture is a rephrasing of is using a camera.
A camera is used to take a picture. prepares to take a picture is rephrased as using a camera.
A passenger is a man on a boat and because the whale is very close he is using a camera to take a picture.