James Nestor, a free diver and author of DEEP: Freediving, Renegade Science, and What the Ocean Tells Us about Usself, gave an engaging talk entitled "Humanity and the Deep Ocean" at The Interval at Long Now in San Francisco.
To illustrate the topic of his talk, Nestor shared some absolutely stunning footage of multiple freedivers interacting with huge but friendly sperm whales trying to communicate using the very loud click language the whales use among themselves.
Nestor explains how free-diving civilian scientists interact with sperm whales and other marine life in ways other technologies wouldn't allow. You can swim just steps away from these giant mammals. Whales, too, miraculously reorient themselves, as if trying to start a conversation. They actually send clicks (recordings of which Nestor is playing on stage) that are used for communication, not geolocation. When you understand how advanced these creatures' brains are, it's not surprising that they have something to say.