Marianas Trench

Only four other national monuments are larger, and they are all underwater as well: Rose Atoll, Marianas Trench, Pacific Remote Islands, and Papahānaumokuākea.

“He was an American original,” Buckley said, “and a dear friend. I always learned something with everything he sent me. There was always a story. His well of stories was deeper than the Marianas Trench.”

The scientists’ dismay is reminiscent of the consternation felt by explorers who found plastic waste in the Pacific Ocean’s Marianas Trench, the deepest place on Earth, during submarine dives earlier this year.

Plastic was even found last month at the bottom of the Marianas Trench, off the Philippines, the deepest place on Earth.

I had once asked the captain how far we were from the Marianas Trench, because each day the sea is exactly the same.