Form and function are tightly knit across the animal kingdom. And if ever there were a being built for the deep, it would be this one.

The sperm whale is the largest predator on the planet, and these long, gray giants are physiological miracles. When their tiny pectoral fins aren’t being used for steering, they lie flush against the body, giving the whale its streamlined shape that resembles a submarine. These living vessels, though, dive deeper than anything military-grade.

When you swim to the bottom of a pool, you begin to feel a difference in pressure against your eardrums. At six thousand feet—a depth these whales frequent—the animals experience pressure around two hundred times greater than at sea level.

The sleek bodies reduce drag, allowing the whales to descend without expending significant amounts of energy. Their lungs collapse to a tiny fraction of their volume at the surface. Air is squeezed into a rigid trachea, where it will sit during the dive, preventing air bubbles from forming in the blood that would otherwise cause the bends. Heart rate and metabolism slow as blood is shunted to the heart and brain, while oxygen stored in myoglobin within the muscles is utilized. Each of these adaptations allows the animals to dive up to two hours as they pursue their prey. 

Clicking sounds that begin at the surface are the last remaining signs of the whales as their shapes fade out of sight into the depths. The idea of it all is as eerie as it is impressive. Stories unfolding below us in the absence of an audience. 

And it’s the mystery of these marvels that keeps me coming back.