Photographer Franco Banfi and his fellow divers were following this pod of sperm whales (Physeter macrocephalus) when the giants suddenly seemed to fall into a vertical slumber.
This phenomenon was first studied in 2008 when a team of biologists from the UK and Japan inadvertently drifted into a group of non-responsive sperm whales floating just below the surface.
Baffled by the behavior, the scientists analyzed data from tagged whales and discovered that these massive marine mammals spend about 7 percent of their time taking short (6- to 24-minute) rests in this shallow vertical position.
Scientists think these brief naps may, in fact, be the only time the whales sleep. Photo by Franco Banfi, a finalist in the 2017 Big Picture Competition.
A behavior that was first documented only back in 2008.When a group of scientists drifted into a pack of completely still sperm whales.
After further studies, they found that this collective nap occurs for approximately 7 percent of the whale's life…In short intervals of just 6 to 24 minutes.
Diver Sabrina Belloni posed next to these majestic creatures.Capturing the immense scale and unique beauty of these underwater giants.
You can see more of the Switzerland-based photographer's underwater photography on his website and Instagram.