Most of us think of waves in fairly simple terms. When they’re small, they roll in. When they’re large, they crash. And when they’re huge, they just might flood the bike path that runs along Lake Shore Drive.

For William Finnegan, a staff writer for the New Yorker and a lifelong surfer, “each wave is a column of orbiting energy” that rises to the surface and tumbles forward as it approaches land. The dynamics are deceptively complex. But if you’re watchful, athletic, and calm under extraordinary pressure, you can learn how to ride waves twice as tall as you.

Finnegan’s new memoir, Barbarian Days, gleams with precise, often lyrical recollections of the most memorable waves he’s encountered. Raised in California and Hawaii, he started testing his limits on a longboard as a young teen and has never stopped, following his obsession across the globe in search of the world’s most stupendous breaks. There have been some stunners, including Kirra, in Australia; Jeffreys Bay, in South Africa; and Ocean Beach, in the shadow of San Francisco’s Golden Gate Bridge. Top billing goes to Fiji’s Tavarua, which when he discovered it in 1978 was “an empty, immaculate coral-reef left, breaking in Edenic abundance.” (It’s now an exclusive resort.)

Although surfing culture has long been dominated by men and tends to attract showboats, this contemplative book is hardly a trophy case of macho conquests. “Defeats, humiliations—craven avoidance—burn into memory so much more deeply, at least for me, than their opposites,” Finnegan writes.

He carefully mines his surfing exploits for broader, hard-won insights on his childhood, his most intense friendships and romances, his political education, his career. He’s always attuned to his surroundings, and his reflections are often tinged with self-effacing wit. Calling his younger self to account for dodging adult responsibility and flirting with death, he’s unsparing but not unforgiving. One day in 1971, a college dropout with a head full of LSD, he paddles out on Maui’s Honolua Bay. “I felt some rapture of the deep,” he writes. “Then the lights went out.”

By the later chapters, surfing has become a soul-cleansing antidote to the horrors he witnesses as a war correspondent in Mozambique, Central America, Bosnia, and Sudan, among other places. A cliffside retreat in Madeira, a Portuguese island off the coast of Morocco, affords him the opportunity to write long-form dispatches without severing his visceral connection to the sea. He positions these two modes of being in opposition to each other: one sedentary, civilized; the other physical, primitive. But the apparent contradiction becomes more of a duality. Whether he’s twisting words into prose or skidding down a wall of water, Finnegan is inexorably drawn to the spots where beauty and terror coexist, and he keeps going back for more.  v