“Shark!” The call went out from someone in the pilothouse, and word spread. Soon, we were all crowded up near the bow, squinting and pointing, amidst a ripple of excited murmuring. The captain slowly aimed the 62-foot wooden boat towards a large white object that bobbed in and out of sight on the surface a couple hundred metres ahead. As we got closer, the truth was revealed: it was merely a dilapidated buoy being tugged by the current. Disappointed, we all dispersed back to our myriad tasks in the galley or back on the dive deck.

It was late April, and by this, the third day of Oceana’s first Channel Islands expedition, I was both relieved and disappointed that we hadn’t yet seen a great white shark. After all, this necklace of eight islands off California’s coast is reputed to be something of a nursery for the apex predators. We’d seen plenty of their favourite prey – sea lions – frolicking in the boat’s wake and playing peek-a-boo in among the kelp. But their absence, while reassuring while bobbing on the surface in dive gear, also emphasised the fragility of this ecosystem, and a reason why Oceana was there.

“These islands are known as the Galápagos of North America,” explains Geoff Shester, Oceana’s California Campaign Director and the expedition leader. “[They’re] renowned for their biodiversity as well as a haven for sensitive species.” Besides white sharks, the Channel Islands are well known as a haunt for the critically endangered giant sea bass, as well as bat rays, angel sharks, various corals, and mammals like elephant seals, all of which call the dense kelp forests and rocky reefs home.

Oceana is one of the world’s most influential ocean advocacy groups, and its American division has primarily focused on driving science-based policy supported by other groups’ hands-on research. But thanks to a recent partnership with the Swiss watch company, Blancpain, Oceana is undertaking three ambitious expeditions of its own to the Channel Islands in 2024 and 2025. The Oceana expedition team is made up of members from its own West Coast ranks, as well as the Philippines, and volunteer scientists from other marine conservation groups in the US and Mexico. I was invited along as a guest of Blancpain, but would have to earn my spot. Using the Ventura, California-based Peace Boat as a floating base camp, we would spend five days on each expedition moving between anchorages among the lesser visited of the islands, diving three or four times a day to perform swimming transects, collect environmental DNA, and capture visual evidence of the ecosystem. “We’re trying to provide more data to show the need for additional conservation measures in this place, and also show the world how amazing it is,” Shester says.

Of course, the best way to ‘show the world’ is through photography, and as one of the only expedition members without a science background, my primary role was to take pictures, and the rich, cold waters around the islands are incredibly photogenic. On a single dive off Santa Rosa Island during the most recent expedition in September, I descended into Caribbean-like visibility, above and through the 20-metre-tall kelp, as if into the canopy of a jungle. Alongside me, another diver carried a tripod-mounted 360-degree camera that she would place on the seafloor. The footage from it would be edited and posted to Oceana’s YouTube channel, allowing viewers who’ve never dipped a toe in the sea to experience what it’s like to dive among this eerie, otherworldly forest.

We dove in dedicated teams, each with a safety diver who helped with navigation. Science divers carried clipboards and waterproof pencils with which to record bottom topography and species as they swam along a tethered and unspooled 30-metre tape measure. Meanwhile another team was devoted to collecting environmental DNA, or eDNA, by filling a sealable bag with seawater for filtering and analysis. And then there were three of us focused on taking photos and video. On that same dive off Santa Rosa, Oceana diver Danny Ocampo, spotted two giant sea bass swimming in the gloom just beyond our range. But no sooner did they disappear came a majestic bat ray, cruising out of the kelp. My head was on a swivel, watching all the action. Anja Brandon, one of the science divers, got my attention, pointing to a waving bed of kelp. I swam close and as the leaves parted, I spotted an enormous decorator crab, its kaleidoscopic colours revealed by my powerful lights. I dutifully documented it on my memory card. Later, on our ascent, a curious harbour seal gracefully spiralled in and out of the kelp. This was one of those dives that you simply don’t want to end.

Back on the boat, while we photographers performed our rituals of swapping batteries, offloading memory cards, and lubing gaskets, Dr. Adrian Munguia Vega, was intent on his own routine. An internationally renowned expert in eDNA, he set up shop on one of the small galley tables and, aided by expedition coordinator, Caitlynn Birch, proceeded to pour the contents of his pouches through a vacuum filtration system. A small filter disc captured the DNA from the seawater, and Munguia Vega would systematically label each filter with the time and location from which it came, then tuck it away for later analysis back at his lab in Arizona. The results of this analysis would reveal all the species that had passed through that water, from sea bass to Garibaldi fish, to crabs, and even, I suppose, us. Between our shallow dives, the Peace Boat would motor offshore to deeper water so Munguia Vega could drop a Niskin collection bottle over the side to gather water samples from as deep as 100 metres. His work is one of precision and patience and, like most science, takes time.

Speaking of time, Blancpain, the main supporter of these expeditions, is the creator of the first true diver’s watch – the Fifty Fathoms – in 1953, and to this day is committed to not only building high quality aquatic timepieces, but is also a leading supporter of ocean conservation, science, and photography. The company’s CEO is an avid diver himself, and its Ocean Commitment programme is dedicated to seeking out worthy partner organisations, like Oceana, with whom to partner. In return, of course they get the exposure generated by expeditions like ours, and ample photographs of their dive watches on the wrists of the scientists in situ, and Blancpain provided several of its Fifty Fathoms watches, which were dutifully strapped on before every dive, timing rings set for our 30-minute bottom times. Call it real world product testing.

The Pacific Ocean is anything but pacific, and diving expeditions are subject to the whims of the wind and the waves. While the April expedition was relatively calm, the water was colder and more murky, typical of that time of year. However, in September, it was considerably warmer and clearer, but we also faced gale force winds and big seas. This meant the Peace Boat’s captains had to play a sort of three-dimensional chess, maneuvering between sheltered anchorages for diving and sleeping, and running between islands when it was relatively safe. Adaptability was key, and we had to swap some dive site choices for others, depending on the capricious daily marine forecasts. It wasn’t only the captains who had to contend with the big seas and wind. The boat’s cook also rose to the challenge, keeping us fed from a tiny, pitching cooktop. The fact that we ate like royalty despite conditions was a testament to his skill.

Expedition life is a distilled experience, enhanced by the close quarters of a small boat, focused work, and physical activity. The days start early with coffee and an early dive, then proceed through familiar routines of prepping gear, diving, eating, downloading photos, transcribing survey notes, maintaining camera gear, filling air cylinders, filtering seawater, and raising and setting anchor at dive sites. Everyone had their tasks, and we fell into a rhythm. Bonds were quickly formed on the April expedition, then renewed in September. The Oceana team is already planning a third outing next November. I’m already hoping we see a shark…

Dive through a kelp forest off the Channel Islands with the Oceana expedition team: