This is how sperm whales sleep, but Matt Kaplan at Nature has the story behind this incredible shot:
A team led by Luke Rendell at the University of St Andrews [was] monitoring calls and behavior in sperm whales (Physeter macrocephalus) off the northern Chile coast when they accidentally drifted into the middle of a pod of whales hanging vertically in the water, their noses poking out of the surface. At least two of the whales were facing the boat, but not a single animal responded.
It was actually pretty scary. The boat had drifted into the group with its engine off [while] I was below decks making acoustic recordings. Once I saw the situation I decided the best thing to do was to try and sail our way out of the group rather than turn the engine on and have them all react.