Hawaii’s Lava Tubes

Diving Hawaii’s Lava Tubes

A decade ago, when then-20-year-old Devin Erickson from Kansas put on his diving gear and slipped beneath the surface of the Pacific Ocean surrounding Oahu, the third largest in the famous island chain, he knew he had found paradise. Eight years earlier, when he was 12, he was thrilled when his father took him on his first dive trip off Jamaica. Devin and his dad enjoyed annual trips to other Caribbean destinations.

But he had never seen anything like this: beams of skylight illuminating soaring lava towers, trenches, tubes, and overhangs. He swam in and around them, marveling at the sea life and the shifting light. There were magnificent green sea turtles picked clean by endemic saddle wrasse, huge spotted eagle rays serenely passing by, black-tipped reef sharks on patrol.

green sea turtle

“It was almost like an entire underwater world lit by stained glass,” Erickson says. Everywhere he turned, the unique lava topography off Oahu surprised him with a new discovery.

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Devin and his girlfriend Taylor, who came from Kansas, had traveled to Hawaii for fun. They couldn’t bring themselves to leave. Now, they are married with four children, and Devin spends his days introducing other divers to his own underwater paradise. He runs an operation called Banzai Divers Hawaii, that specializes in small groups and shows beginners the ropes.

One of his favorite places to share is Nanis Reef. The name means “beautiful.”

“It’s the perfect description,” he says. “Hop between a series of three basin-like formations, each with its own unique marine life. See how many giant titan scorpionfish you can count in the far one. Stop in the middle one to try your luck at spotting the illusive octopus. Finish it off in the last basin, peeking under ledges for slipper lobster and banded coral shrimp.”


Devin normally makes three dives each day when the conditions are good, starting at 7 a.m. and wrapping up by mid-afternoon. Children must be at least 10 years of age and accompanied by an adult. His intimate classes start in calm, shallow water, where students learn about the gear and how to use and store it properly. Successful completion of the three-day course culminates in an exciting open-water diving experience to see the wonders of lava tubes (see box). Graduates are certified by the Santa Margarita, California–based Professional Association of Diving Instructors (PADI)—the world’s largest such organization—and are allowed to dive here and in other destinations to 60 feet.

Hawaii’s Lava Tubes

Erickson has taught men and women in their 90s to dive. He has led dives for individuals without arms and legs. “They are weightless,” he says. “Once you are in the water, anyone can do it.”

What is a Lava Tube?

When red-hot molten lava—pele in Hawaiian—flows beneath the surface of hardened rock and cools, it creates a crust around itself. Over time, erosion results in spectacular but rarely seen underwater tunnels, caverns, arches, pillars, and trenches that are spread throughout the north coast of Oahu. —T.R.P.