Louise Wholey doesn’t seem to have heard the news that aging is difficult, diminishing and a total bore. At age 80, she can still hoist her scuba tank onto her back from a sitting position if she maneuvers it right. Right now, she stands, then penguins around to peer out toward the ocean, and I follow her gaze, clutching my new fins and mask. I have just recertified in scuba diving after a long absence from the water (20 years).

Today in Monterey Bay the visibility is a murky 15 or so feet, and it soon drops below that. The effect is of a slightly menacing but beautiful fairy forest, where dark shadows resolve into rocks covered in orange anemones as you get closer, and the kelp looks like deformed trees behind which a gingerbread house or a monster might lurk. It’s quiet except for the roar of my own breath on exhale, and everything moves in slow motion — the gentle sway of stipe, the dance of anemone arms. Huge starfish drape themselves on rocks, and now and then a fish as large as my hand darts by. At one point, a whole school envelops me, and it feels as if I am shooting through space among asteroids. Also always present: the voracious urchins, purpled proof of climate change, strangely beautiful, devouring kelp quietly, relentlessly. Throughout, I keep a close eye on Louise. I don’t want to lose her in the murk, because it would be embarrassing, for one, and also unnerving to be suddenly alone in this dark and silent world.