“Who has known the ocean? Neither you nor I, with our earth-bound senses,” Rachel Carson wrote in her pioneering essay Undersea in an era when the deep ocean was more mysterious than the Moon. The essay became the basis of her lyrical 1951 book The Sea Around Us, which won her the National Book Award and which she dedicated to William Beebe (July 29, 1877–June 4, 1962) — the visionary naturalist, ornithologist, marine biologist, and explorer who in the 1930s became the Poseidon of deep sea exploration.

Diving off the coast of Bermuda in the Bathysphere — a pioneering spherical deep-sea submersible that looks like something out of a Jules Verne novel, named after the Greek word for “deep”: bathús — Beebe became the first scientist to observe the creatures of the deep in their native environment.

No human being had ever ventured deeper into the blue abyss.

He saw strange and wondrous creatures defying all earthly imagination, menacing and beautiful as they moved through the inky waters sleek and jawed and tentacled.

He saw an alien world at the bottom of the world.

In his 1934 account of the dive, Half Mile Down (public library | public domain), Beebe channeled the raw astonishment of it all. “Only dead men have sunk below this,” he gasped at 600 feet, then wrote:

Ever since the beginnings of human history, when first the Phoenicians dared to sail the open sea, thousands upon thousands of human beings had reached the depth at which we were now suspended, and had passed on to lower levels. But all of these were dead, drowned victims of war, tempest, or other Acts of God. We were the first living men to look out at the strange illumination: And it was stranger than any imagination could have conceived. It was of an indefinable translucent blue quite unlike anything I have ever seen in the upper world, and it excited our optic nerves in a most confusing manner. We kept thinking and calling it brilliant, and again and again I picked up a book to read the type, only to find that I could not tell the difference between a blank page and a colored plate. I brought all my logic to bear, I put out of mind the excitement of our position in watery space and tried to think sanely of comparative color, and I failed utterly. I flashed on the searchlight, which seemed the yellowest thing I have ever seen, and let it soak into my eyes, yet the moment it was switched off, it was like the long vanished sunlight — it was as though it never had been — and the blueness of the blue, both outside and inside our sphere, seemed to pass materially through the eye into our very beings.

Complement with Carson on why the sea is blue and her almost unbearably beautiful meditation on the ocean and the meaning of life, then revisit artist Else Bostelmann’s stunning scientific illustrations of what the Bathysphere saw.