Astove Atoll: A Pristine Divers Playground in the Seychelles

Divers silhouetted behind a large colony of magnificent anemones at the Sam’s Ultimate site.
Divers silhouetted behind a large colony of magnificent anemones at the Sam’s Ultimate site.


He’s starting to specialise in being present when pristine Indian Ocean atolls open to the public – now MARK HATTER gets in at the start in Astove, a remarkable divers’ playground

Divers silhouetted behind a large colony of magnificent anemones at the Sam’s Ultimate site.

WITH AN INTERNATIONAL diving market seemingly flooded with pedestrian destinations and cattle-car operations, it’s no small wonder that I once again find myself on a remote Seychelles atoll in the Indian Ocean, completely off the grid, in search of something special.

It’s March, and I have hooked up with six other explorers as the first guests to publicly dive Astove Atoll’s newly established Coral Lodge, in the Seychelles Aldabra Island group.

Three years ago it was a new diving operation on Alphonse Atoll in the Seychelles’ Alphonse Island group that attracted my attention (Opening Up Alphonse, June 2015). Then, as its first public diving guest, the divemasters and I explored sites that had perhaps never been seen by humans before.

And so I promised myself that if other venues in the Seychelles out-islands opened, I would try to be on the leading edge of that opening

Enter Blue Safari (the parent entity to the Alphonse Fishing Company and now operator of the diving venue on Alphonse) and Astove. Another 250 miles south-west of Alphonse and about 500 miles from Mahe, Astove has been considered a best-in-class fly-fishing destination for more than a decade.

With a small, efficient infrastructure, the atoll’s lodge catered to a maximum of six anglers booking seven-day trips between November and April until March this year. That’s when significant improvements were completed, including a paved runway to allow bigger planes and payloads (read extra weight-allowances for divers’ camera gear) opening the atoll to diving operations.

I’D FIRST MET AND DIVED with Blue Safari’s Diving Operations Manager Sam Balderson on Alphonse. Sam would lead our inaugural trip to Astove and we met under the Alphonse runway cabana (all flights to Astove refuel at Alphonse).

I also met the other divers in our group, already on Alphonse to get in a few days’ diving before heading to Astove.

As the plane gassed up, Sam made introductions and filled us all in on Astove’s opening to public diving.

“The diving plan for Astove has been about two years in the making,” he told us. “That plan includes shutting down fishing operations during the week our divers will be booked.” This was surprising and very good news; I had wondered how the lodge would manage both anglers and divers simultaneously, even though the fly-fishing is land-based.

“As far as I know, it wasn’t until December 2017 that anyone dived extensively around the atoll cataloguing prospective sites,” continued Sam. “I was the lucky one to get that task.”

So armed with a chart, some anecdotal notes from a few private boats that had passed through Astove and a GPS, Sam set out last December to pre-dive a handful of promising locations around the atoll. His findings would allow our team points of departure to help us more fully explore these pristine reefs.

To say that Astove is totally unexplored would be inaccurate. Famously, it was Jacques Cousteau in his 1959 production of The Silent World that brought the Aldabra Group to the public eye, and recently Nat Geo teams have visited to film their Pristine Seas series.

That said, one could reasonably argue that it’s only the infrequent privateer, Nat Geo, Cousteau, Sam and the seven of us that have had the chance to witness Astove’s underwater treasures.

A pair of elegant Myer's butterflyfish at the Mouth.
A pair of elegant Myer's butterflyfish at the Mouth.

The experienced divers in our group would later be unanimous in declaring that Astove’s reefs are as close to pristine as likely exists in a current environment of climate-change, pollution and exploitation.

The proof lay in our observations and images collected over 17 dives at eight dive-sites circling the atoll.
More specifically, the measure of health and fitness in an environment can generally be assessed by the abundance and balance of sea-life, from the lagoon and grass flats to the adjoining reefs and drop-offs.

From plankton-feeding anthias, grazing surgeonfish and coral-crushing parrotfish to apex predators such as the uncommonly large and uncommonly numerous potato grouper and saddleback cod, Astove health indicators point to a strong and vibrant eco-system.

Most importantly, the stony corals are healthy. Where recent global-bleaching events have impacted or devastated much of the world’s remaining stony corals, Astove is something of an oasis, seemingly immune to warming surface waters. The answer to its robust resistance might lie in its isolated geography, set as it is in very deep ocean.

The reef plunges almost vertically from the surface to thousands of metres deep on the western side of the atoll, and slopes steeply from the eastern shore, with surprisingly cool currents pushing over and around the atoll almost daily.

Generally one would expect cooler currents during the stronger spring tides, yet we experienced them even during the weaker neap tides.

And the thermoclines were impressive, often as much as 4°C (from 28° to 24°) beginning in as little as 10m depth.

Whether our observations were simply anecdotal or scientific, what was clear is that Astove is a coral-reef oasis in an ocean under ever-increasing stresses.

As a bonus, it even has a species of endangered sharks. We encountered these scalloped hammerheads off Astove’s only named site, Hammertime. Sam had gleaned the name and location from some historical notes and a pre-dive in December.

The dive begins at an encrusted anchor-chain draped over the wall, the remains of a 19th-century shipwrecked Norwegian whaler.

From there, divers drop to 20m, then off the wall into blue water, typically just out of sight of the reef, and wait. According to Sam, the best opportunity to see the sharks is in the early morning.

ACCORDINGLY, for our first dive of the trip, we got an early wake-up call, stuffed berry muffins and coffee into hungry bellies, then rolled from the skiffs into clear water just after 7am.

The sun was barely up, and it was just light enough to see the chain and follow it over the wall into the abyss.

Following Sam’s protocol we hovered, neutral, far enough off the wall that we could no longer see it, in the indigo water.

Soon, the ephemeral shapes of a half-dozen scalloped hammerheads dissolved in and out of the 10m lateral visibility.

They remained wary and kept their distance. It wasn’t the photo-op for which I’d hoped, but it was pleasing to kick off the week with a pack of rare reef A-listers.

We lingered before moving back to the wall and found that the current had accelerated, pulling us at an exhilarating speed toward the north end of the atoll.

We covered nearly half a mile in our remaining 30 minutes’ bottom time, passing all manner of colourful and stony coral formations, outcroppings and channels leading from the interior flats to the outer reef. The biomass we passed along the way was impressive.

In one wide channel near the end of the dive, the current billowed up powdery white sand, generating an underwater snowstorm. And, as we raced our way along the wall, it was comforting to hear the skiffs motoring along above us, following Sam’s SMB.

After our three-minute safety-stop we clambered into the skiffs, fist-bumped, and chortled on about the many cool things we had sailed by on the dive.

It was barely 8.30, and we still had the entire week ahead of us.

While Hammertime’s sharks were cool, the slow and very close drive-by encounter we had later in the week by an even more rare, 3m-plus great hammerhead shark at the Mouth (the narrow, shallow channel leading from Astove’s inner lagoon) was epic. Naturally, my camera was rigged for macro images!

Throughout the week at several of the sites on the western wall, silvertip sharks would come in for a quick inspection early in our dives, further testament to the health of the marine eco-system. Should that have been in any doubt, the plethora of green and hawksbill turtles that accompanied us on every dive also proved the point.

A diver along the reef wall at Magnificent City.
A diver along the reef wall at Magnificent City.

Sam had certainly done his homework regarding spectacular and varied dive-sites. And his innate British talent for underselling expectations became the delight of our dive-team as the week progressed.

“I found a spot on the wall that has a few anemones,” he told us during the pre-dive briefing on the second morning. Sam’s “few anemones” were, in reality, a virtual city – score of animals, Heteractis magnifiica, replete with multi-families of Amphiprion akallopisis (skunk anemonefish) carpeted an area of 25sq metres. I had heard stories of large anemone colonies in the Indo-Pacific, but had never encountered one of this impressive magnitude.

The following day Sam briefed: “We have calm seas this morning, so I want to show you a reef on the eastern slope that has some soft corals.”

Of course, we found his reef with “a few softies” to be a vast forest of rainbow pastel-coloured Dendronephthya beginning at 20m. On the dive I followed the lush formations deeper, musing rhetorically: “Why is it that impressive formations like this soft-coral forest only get better with depth?”

If only time and physics would have allowed me to see just how deep that forest grew.

THE ABSENCE OF an official dive-site name needed to be addressed, so later in the week over cocktails and wahoo sushi, we voted on some in the interests of consistency for future divers.

The largest anemone site, directly across from the Lodge’s compound, was named Magnificent City. And we all agreed that Sam’s soft coral forest, so impressive and so understated, should be named, in his honour, Sam’s Ultimate.

The name derives from a famous and particularly vibrant dive-site in the northern Coral Sea known as “Carl’s Ultimate”, named after underwater photographer Carl Roessler.

I wondered how the Astove oasis, so small, so remote and so special, would fare as the suffocating walls of human exploitation continued to squeeze the planet. I put this to Blue Safari managing partner Keith Rose-Innes and was intrigued by his thoughtful response.

“Keeping a minimal presence on the out-islands is critical to preserving their near-pristine states,” he said.

“If the out-islands like Astove, Alphonse, Cosmoledo, Assumption and others are left completely uninhabited and wild, they surely would be targeted for illegal exploitation.

“The Seychelles island groups are geographically too widespread to expect effective government protection enforcement, regardless of the laws and punishments.

“If Blue Safari is a responsible steward of the islands we lease for tourism activities such as diving and catch-and-release fishing, while maintaining a minimal footprint, then just our presence here is a deterrent to unlawful activities that would occur if we were not present.”

This useful observation post for the Seychelles government is also conscious of the need for clean energy solutions.

On Alphonse the need for diesel-power generation for 98% of the island’s needs has been replaced by installing solar panels.

Construction of rainwater-reclamation facilities is also underway to eliminate the need for a power-hungry desalination plant. “Astove is next,” Keith tells me.

Our conversation leaves me confident that, for now at least, the atoll will remain a vibrant oasis in an imperfect world.

But Keith had another surprise – Blue Safari now plans to expand its Seychelles diving operations to Cosmoledo Atoll, with a lift-off date of December this year.

“Cosmo” is Astove’s big sister, 19 nautical miles north-west. The Alphonse Fishing Company has been operating liveaboard fly-fishing expeditions there for more than a decade.

Cosmo’s reefs are virtually unexplored and its marine eco-system is, presumably, also near-pristine, and being roughly four times the size of Astove, the diving possibilities grow geometrically. With the eco-responsible blueprint of Blue Safari, what’s not to like about that plan?

Which leaves me with a welcome dilemma. How do I change my plans for this December to be part of that launch party?


GETTING THERE: Direct BA flight from the UK to the Seychelles, or other carriers with a single stopover to get to Mahe. From there, an IDC charter-flight arranged by Blue Safari takes you to Astove, but there are weight restrictions.


WHEN TO GO: The diving season runs from November to April.

MONEY: Seychelles rupee while on Mahe, US dollars or credit card on Blue Safari’s out-island locations.

HEALTH: The nearest chamber is on Silhouette, about 2.5hr flight from Astove.

PRICES: Return flights to Mahe from £775. Blue Safari offers a one-week leisure package with flights from Mahe and full board at Astove Coral House (two sharing) for US $9345pp (43% of which is down to the $4000 airfare levied by IDC). A 10-dive package costs $1135 pp.

VISITOR Information: Experience Seychelles


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