Blackwater diving off the coast of Hawaii offers a truly unique underwater experience.

“Don’t be alarmed by the parachute – it’s definitely a bit unnerving!” warns Sarah Matye, a seasoned marine biologist, as she prepares a group for one of the most extraordinary scuba adventures on earth.

“It’s quite a shock when you’re accustomed to spotting tiny creatures, only to look up and be faced with something that resembles a massive 30-foot jellyfish!”

She further explains the reason for using a parachute during the dive, and no, it’s not because the ocean floor is 5,000 feet below.

This dive, known as the 'Pelagic Magic' dive by Matye’s company, Jack’s Diving Locker, is often referred to as the 'blackwater dive' by other operators.

The dive takes place under the cover of night, approximately three miles off the coast of Kailua Kona on Hawaii’s ‘Big Island,’ a land shaped by towering volcanic mountains that descend sharply into the deep ocean.

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Turbulent currents

Offshore waters are driven by swirling gyres, which carry everything in the water in a different direction than the boat above, pushed by the wind.

The parachute, deployed underwater, secures the boat to the sea currents, ensuring it stays anchored and doesn’t drift away from the divers.

For added safety, all six divers are tethered to the boat. This is less about preventing them from being swept away by the current, and more to ensure they don’t descend beyond the 50-foot length of the tether.

Most scuba dives occur on coral reefs or other stable substrates, which naturally limit divers from exceeding their physiological depth limits.

But this dive is different.

“Please don’t drop your light or camera,” Matye urges. “I’m not diving down 5,000 feet to fetch it for you.”

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Complete darkness

Matye’s partner, Jeff Milisen, who leads similar dives with Kona Honu Divers, says, “For some, it’s like being in ‘Star Trek.’ For others, it’s the incredible thrill of discovery and exploration.”

“There’s something truly unique about being out there, knowing there’s an entire world of creatures beneath you that no one has ever witnessed.”

Matye and Milisen stay in constant touch with scientists who study the gelatinous plankton, juvenile fish, and invertebrates that drift through Kona’s surface waters at night.

They’ve captured photos and collected specimens of several species that have never been documented before, and research studies are now underway.

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‘Alien’ fish species

“This is the largest migration on Earth,” says Matye. “And it happens every night. These creatures are rising up from the mesopelagic zone.”

This region of the ocean, often referred to as the Twilight Zone, stretches from about 660 to 3,300 feet deep and is home to creatures that are undeniably strange.

“This is the most extraordinary dive you’ll ever experience,” Matye adds. “We often encounter creatures that are completely unknown to science. You’ll become part of an exclusive group of blackwater divers who’ve done this.”

While most of the divers are experiencing this for the first time, Thomas Kline, a fish photographer from Alaska, is on his twelfth blackwater dive tonight.

He’s eager to capture images of creatures he’ll never encounter in the salmon streams back home.

“I photographed a phronima on one dive,” he recalls. “It’s the creature that inspired the alien in the ‘Alien’ movies. When it feeds, its mouth parts actually extend, just like the alien in the film!”

Thankfully, the real-life version of this alien-like creature is only about two inches long, unlike the monstrous beings most night divers imagine lurking just out of sight beyond their lights.

Once we’re in the water, the initial feelings of paranoia fade away, and the “Star Trek” comparison begins to feel particularly fitting.

It feels as though we’re journeying through an endless universe, with tiny moons, galaxies, and alien creatures drifting by us.

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Uncommon fish species

Comb jellies ripple with rows of delicate, thread-like organs that refract light into sweeping rainbows of color.

“Net-caster” jellies, longer than my entire body, suddenly shrink to just a few inches and zip away into the darkness.

Creatures resembling jellyfish with stinging tentacles turn out to be larval fish that grow intricate filaments to trick predators into thinking they’re venomous jellyfish.

The sheer variety of life feels overwhelming.

Yet when I resurface, and Matye asks what I saw, I can’t identify a single creature. Everything was completely unfamiliar.

“I’ve done over 150 of these dives,” Milisen tells me, “and every single time, I see something completely new.”