Exploring the Upside Down: What It’s Really Like on Kona’s Most Extreme Scuba Dive

The weird and wonderful creatures that populate Hawai‘i’s offshore waters are visible each night on this black-water dive.


Box jelly

A sea wasp (box jelly) maneuvers through the nighttime waters off Kona. Photo: Jeffrey Milisen


Scarcely 2 miles off shore from downtown Kailua-Kona under a blanket of cloudy, moonless darkness, seven scuba divers—including an expert guide and myself, a first-time black-water night-diver—zip up their wetsuits, fumble with their fins and turn on their air tanks with a hiss as they prepare to dive into the unknown. Such a cliché—the unknown—but here, it fits.


Within sight of the orange astronomy-sensitive streetlights peppering the slopes of Hualālai and Mauna Loa, our group, led by Jack’s Diving Locker, is about to cross into a realm so vast, different and out-of-mind for most that it might as well be the Upside Down alternate dimension from Netflix’s hit Stranger Things. The motor cuts and the hollow thud of waves lapping against the boat’s flanks mingles with the echoes of my own quickening heartbeat like a badly performed drum circle. I ask Capt. John Caron for the depth where we’ve stopped: “Maybe 4,000 feet? It’s too deep for a Fish Finder-style depth finder—you’d need something pretty sophisticated to get an exact reading out here.” Perfect.


Naturally, this activity is not for everyone—it takes considerable willpower to override the wailing self-preservation banshee in one’s head to willingly board a boat in the dark and then jump overboard into the fathomless depths to visit beings quite literally undescribed by science. But that’s exactly the appeal—and I’m in expert hands.


“If I could do one dive for the rest of my life, it would be this one.”
— Sarah Matye, dive leader



Feisty and seemingly fearless, dive leader Sarah Matye told us in the dive briefing, “If I could do one dive for the rest of my life, it would be this one.” And I believe her. With hundreds of these dives under her belt, she’s become one of the go-to local experts for identifying the weird and wonderful that emerge from the depths to shimmer in divers’ lights. She explained the appeal of a dive without the reference points of a reef: We’re here to witness the world’s largest migration, she explained, the daily greener pastures of plankton rising from the abyssal epipelagic zone to the surface waters to feed, frolic and interact. And the cast of characters on display defies logic and reasonable description. There are bioluminescent pyrosomes, wormlike siphonophores, gelatinous Venus girdles, long chains of toilet-paper-tube-shaped salps and, if you’re lucky, a salp parasite called Phronima—the inspiration for the terrifying being in the movie Alien. Let’s do this, I thought, and took one giant stride into the Upside Down.


I attached myself to the rope line connected to the boat with a carabiner clip and sank into the black water, frantically flashing my light every which way, trying to make sense of the inky space. The water looked like a nighttime snowstorm on the Mainland, the kind with big, puffy, slow-moving flakes. Until you learn to adjust your focus and realize the flecks—most tinier than your pinky nail—are the main attraction, you’ll be underwhelmed. “Look for anything shiny around you,” Matye had told us in the dive briefing. “Even if you can’t find its eyeballs, its gut system or see how it moves, it’s alive. And it’s awesome.” And until you learn to quit flailing about,  flashing your bulb everywhere, I realized, the only thing you’ll do is dissolve the delicate creatures around you before you have time to appreciate them. “Just be selfish; they’re your animals. They’re tiny, they’re clear and they’re drifting,” Matye told us back on dry land. “By the time you find another diver to show them, they’re gone. Just hang out with it.” So, I steadied my breath and just observed.


Blackwater diving

Dive leader Sarah Matye goes eye-to-eye with a mesopelagic squid called Ancistrocheirus. Photo: Jeffrey Milisen




“These pelagic organisms are really not studied that much,” says Steven Haddock, a senior scientist at the Monterey Bay Aquarium Research Institute who regularly does open ocean dives off  Kona for his pelagic plankton research. That seems to be an understatement. There are currently no comprehensive guidebooks to help divers identify the wild and weird invertebrates they’re seeing out there, and even if there were, there wouldn’t be much information to include alongside the creatures’ photos. Haddock says while his group tends to see the same kinds of organisms over and over again on their research dives, “we haven’t gone through the formal process of giving them all scientific names yet … pretty much every dive we’ll see many things that are not formally known to science.”


To find out if there is a physical database of some of these creatures, I contacted Holly Bolick, collections manager of invertebrate zoology at Bishop Museum, which houses the most extensive collection of marine invertebrates in the Pacific region and the only collection in the world devoted solely to marine invertebrates of the tropical Pacific. She told me: “The Bishop Museum’s Invertebrate Zoology collection does have a few pelagic samples, but they are unidentified bulk samples that were caught using a plankton tow net back in the ’70s and ’80s … we have not received any pelagic collections in over 20 years.”


Unknown, indeed.


“Pretty much every dive we’ll see many things that are not formally known to science.”
— Steven Haddock, Monterey Bay Aquarium Research Institute


When people see the insane body patterns of these plankton, Haddock says, “you get these news items saying, ‘weird half shrimp, half fish,’ or ‘half snail, half jelly fish found,’ and they’re describing a salp or something. They struggle to find the right metaphor to explain these things even though they’re just so common and out there.” The crazy thing is the pelagic zooplankton spotted on black-water dives are not just common, Haddock says, but, because the open ocean is so huge and so vast, these alien creatures are actually “some of the most abundant organisms on the planet.” And, in Kona, thanks to its relatively new island topography with dizzying steep drop-offs close to shore, they’re easier to access than almost anywhere else in the world, and just waiting to be observed.


While exhilarating as a recreational dive for scuba enthusiasts, Kona’s black-water night dives also allow scientists to observe these incredibly delicate and intricate creatures and their equally intricate interactions with one another, without the bothersome hassle of having to harvest them and keep them alive and happy in the lab. “In the daytime, they’re all so transparent and when the background is bright and you’re not able to shine a light on things, you’re not able to pick them out against the background,” Haddock explains. Plus, they’re not always living that high in the water column. “Black-water dives are great for photography.” For these creatures, it’s not the dark that inspires terror, it’s the light, which allows them to be seen and more easily swallowed. “I like to think of their vertical migration in the other sense,” Haddock tells me. “They would live shallow because there are more resources, but they seek refuge down in the dark during the day.” In their dark world, we’re the alien interlopers.


Blackwater diving

A tiny larval lobster hitches a ride on the bell of a jellyfish. Photo: Jeffrey Milisen




By the end of my first black-water dive—having seen a massive jelly with tentacles longer than I am, balls of undulating fish rising and falling into the dark, bright-eyed larval fish drawn to my light like moths to a flame, and so many planktonic drifting creatures that defy description—I was hooked. The weightless feeling, floating in the dark water column, all of it. I couldn’t get David Bowie’s “Starman” out of my head (or get rid of the hand cramp from clutching my dive light for dear life for more than an hour). I had to try it again.


It took several months before I could coordinate a second black-water night dive. I sat patiently through Matye’s briefing, recognizing the cast of characters from my first go-round. “You’ll even see some creatures that may look familiar from the reef, only in their juvenile stages. Here’s a larval lobster,” she said, flashing a very unlobsterlike image on the screen. “It’s got these tiny little eyes, and a tiny little baby tail that grows a lot more deliciouser as they get older.” She continued: “This is a siphonophore. Science doesn’t care about siphonophores. They don’t even have a common name. So I’ve nicknamed them ‘the netcasters.’”


As the briefing wound down and we began to pack up and head for the boat, someone asked the inevitable question: “What about … um … larger creatures?” Matye said: “We’re in the ocean. Weird things happen. But shark sightings are super rare. I’ve only seen them on 2 percent of my dives. If we’re lucky enough to see one I’ll bang my tank to get your attention. Please pay attention. And if it seems overly inquisitive I’ll send you up one at a time.” Then she added, thoughtfully, “It’s best not to be in the open ocean at night splashing around.”


It was, of course, that last bit of advice that reverberated in my brain when I overzealously suited up for the dive on the rocking boat in record speed and found myself the first one ready to enter the water. “Go ahead,” Matye said. And in I went—no splashing at the surface for me.


Blackwater diving

This deep-sea “hula skirt siphonophore” is actually a colony of animals. Photo: Jeffrey Milisen



All at once I became the solo “Starman,” floating in space. I remembered to hone my focus to find tiny little pteropods and swirling unnamed worms. The other divers sank down around me, but I scarcely noticed. I was on another planet. I found my calm. That is, until … DING DING DING.


I looked for Matye, but I’d already caught what the clanking was about. A slender 7-foot shark skated scarcely a foot below my lime-green fins. A blue shark, I would later learn. Weirdly—and maybe it was because I was already in a place so foreign that nothing could surprise me—I wasn’t afraid. This shark was gliding through our group in a way that seemed nonthreatening. It was an observer—as we were—checking out this collection of lights and sound that dropped down suddenly from the realm above.


We did end up having to abort the dive. The shark made several passes and kept coming back. Could I blame him? To this shark, we were probably as weird and wonderful as the pelagic plankton was to us. As I ascended in a cloud of bubbles, I saw Matye way down below give the shark a body check to get it to move away from the divers as they rose to the safety of the boat. “It was like pushing a cow,” she later said. “That thing was a solid wall of muscle!”


We flopped into the boat, one at a time, like fish out of water, and hurriedly packed away tanks to make space for the others. Once everyone made it back on board, we couldn’t stop talking about the shark. “Holy cow, can you believe that?!” was a common refrain. “Seeing sharks on pelagic dives is so rare!” Matye said. I felt incredibly lucky. I wasn’t even sad when we had to motor home after the short 15-minute dive.


The truth is, with pelagic dives, it’s hard to know what you’ll find when you take the plunge into the deep. Each briefing reminds divers that “no two dives are the same.” Now, when I glance out into the ocean at night, I can’t help but see it for what it holds—salps, siphonophores, jellies, pteropods, Venus girdles and, yes, sharks, all mixing and mingling and existing beyond our line of vision. I can’t wait to drop into it again and see what the night churns up next.



By the Numbers


Photo: Thinkstock


  • According to Steven Haddock’s research, 76 percent of the organisms seen on a black-water night dive can make their own light.
  • The average one-tank black-water night dive with a commercial dive outfit in Kona costs $175.
  • 60–80 minutes is the length of an average black-water dive.
  • Boats departing Kona tend to drive 2 to 3 miles offshore before reaching the ideal depth for the dive: between 3,000 and 8,000 feet of water.
  • 2 in 100: The frequency that sharks are spotted on pelagic dives, according to staff at Jack’s Diving Locker. (There have been zero shark attacks on black-water divers in Kona.)



How and Where to Take the Plunge

Manta Ray

Photo: Thinkstock



Most dive outfits in Kona offer the experience as a single-tank dive, while some couple the black-water night dive with a manta ray night dive. All Kona black-water dives include tanks and weights, six-person dive groups, lights and guides. Remember: If you’re making a trip of it from other islands, dive-certifying agency PADI recommends allowing at least 12 hours after a one-tank dive or 18 hours after a two-tank dive before your return flight.


Kona Honu Divers offers a one-tank black-water dive every Friday and select Wednesdays with departures at 8:30 p.m. Charters require a minimum of two certified divers to run and all participants must have a minimum of 50 logged dives.

$169, konahonudivers.com, (808) 324-4668


Jack’s Diving Locker runs branded “Pelagic Magic” dives run on Tuesdays, Thursdays and occasionally on Saturdays during peak times over the summer and winter holidays. Charters meet at 5:30 p.m. (September through March) or 6 p.m. (April through August) and feature an hourlong dive briefing including highlights of ocean ecology. Open to all confident certified scuba divers.

$175, jacksdivinglocker.com, (808) 329-7585


Big Island Divers offers a one-tank dive ($169) or a two-tank manta ray and black-water combo ($249) on Mondays and Fridays to open-water-certified divers with a minimum of 25 logged dives and a prior night dive with their group. Groups meet at the shop at 4 p.m. Strobes and focus lights are available for rent.

bigislanddivers.com, (808) 329-6068