You can see it from the surface of the water: a blue outline 50 feet down. Aquarius. The last undersea base. Diving down to it is like falling slowly into another world.

I wish I could live there. The fish would be my neighbors. The sky would always be blue—if a little wet. And, instead of a stroll, I'd just go for a swim. This Saturday, I watched Aquanauts move in. And then it was my turn. I threw on my gear and hit the water.

The visibility was 60-70 feet, as it often is in here. I could see schools of fish gathering around the habitat's hull; it looked like an Airstream—if an Airstream was designed to be towed behind a nuclear submarine.

As soon as we drop below, the clock starts its count down. Since I am not diving saturated—as the Aquanauts are—I can only stay down for 82 minutes. Aquarius' base is 60 feet below, on the bottom of Conch Reef, but it's less than 2 minutes to the entrance, which is at 48 feet. That leaves 10 minutes to change out of my wet clothing and 10 minutes at the end of the visit to get out and get back to the surface. And about an hour in the base itself. One mustn't dawdle outside with the fish.

Sixty minutes it is. Within a few seconds we're at 30 feet and it becomes clear: This base isn't just an 80-ton steel cylinder, 43 feet long by 9 feet wide.

It's alive.

In its 20 years of operation, the base has gone from being a pristine piece of yellow painted metal—an alien outpost placed here by man—into an overgrown native of the reef, where sea life and humans live side by side. Fish hang out and pass by every viewport all day, unafraid of the humans inside or visitors like ourselves. Corals grow onto bolts and view ports need to be scraped free of biofouling every week or so using 3m non abrasive pads.

I swim into a crawlspace under the base and look up into the liquid mirror of a moonpool. The reflection is perfect save the rippling effect from the water dripping down from above the airlock.

When my push my face through the mirror, I am met by the strangest thing: Air. You've seen moonpools in those killer shark movies: They're the boundaries between ocean outside and the base within. Water is kept at bay by the Aquarius' pressurization, 2.5x that of sea level air. It's amazing that this actually works. If the air inside, which is not musty or humid as I thought it would be but thick on its own accord, were to be the same pressure at sea level while the air lock was open, the base would flood. The air is so dense that my voice registers higher.

The room is amazing. It looks like a lower room in the hull of a great ship that sits below the water line. Everything is still, save for the dripping. Looking down, fish have reformed their school in the water by the time I hang up my dive gear, strip off my neoprene top, kick off my booties and stow my camera in a bucket of water so its seal won't be broken by the pressure.

Before I put on a dry shirt, I rinse off the salt water in a shower that faces a viewport filled with more fish and a wall of air supply valves. The fresh water is hot, piped in every 3 days into a 300 gallon tank by the same support boat and divers that escorted me below.

There's an airlock that is sealed during the exit decompression session. And a working space with emergency air masks. Each door is controlled by a pneumatic system with handles nearly rusted through.

Inside the main cabin, I meet the Aquanauts.

The Aquanauts on this mission are filmmaker and explorer DJ Roller, Scripps Oceanographer Dale Stokes, Professor of Marine Science Mark Patterson, Marine Biologist and National Geographic Explorer-In-Residence Sylvia Earle, and two Aquarius dive techs: Ryan and James. They arrived without luggage, which gets sent down earlier in paint pots that are bolted shut.

The day before their descent, they placed their clothing, computers, cameras, dive equipment into garbage bags that would be "potted down" into the habitat. They each had to decide what to bring, since space is limited in the habitat. Books are a luxury and some were left behind. Food was potted down, too, which mostly consisted of snacks and junk, with a few fruits that would last. Peanut M&M's were sent in a ration of "at least 3 pounds." They're going to be here for a while. "This place gives us the gift of time," says Earle.

View gallery »

Why stay down so long? It's like the difference between vacationing in a country and being a foreign exchange student there. You start to see things like a native. Earle explains: "Actually, seeing a fish eat another fish is pretty uncommon. You have to be there at the right moment and they have to be accustomed to your presence. One thing I love about this place is that the fish really seem to accept the people that come around, even though the people put off a lot of bubbles which usually put fish off. And they don't just run off at high speed. It's more like life around a reef that has never been seen by humans. "

If Aquarius closes, there's no other habitat like this in the world which can allow for embedded observation over long periods of time.

It's hard to fathom any other place like this above water either. The interior's strange mix of creature comforts, scientific equipment, and knobs and dials that literally keep you alive. It's eerie and magnificent to walk through the place:

There's a kitchen on the left with a microwave. Above: stowage for dry food.

There's a galley that seats four at an aluminum table, with a generous view port.

There are two desks, one with a direct phone line to the "watch desk" and one to the outside world via voip across the internet connection, which I measured, casually, at almost 10mbps up and 1mbps down. It's mostly used to transmit video.

The wi-fi network is unsecured, but good luck connecting to it from outside of the base.

There's an air-mix controller and a fridge, filled mostly with M&Ms, eggs, and cheese. There's no beer. It isn't allowed.

The far end of the base has 6 bunk beds, three on a side, flanking another view port with what the Aquanauts call a "2 million dollar view."

I had a plan to get a lot of reporting done on this first trip. I fail. I am overwhelmed by the place's sense of wilderness and hostility and disregard for man's need for air and the habitat's comfort. Within seconds, it already has become another home.

I record some clips, take some polaroids, post something on Instagram.

DJ roller gives us a tour of the endless knobs, pressure control systems and electrical controls.

And then, it's already time to leave. My 60 minutes are up.




Mission Aquarius is our week-long trip to the world's last remaining undersea habitat: Aquarius Reef Base.

Brian Lam is an ocean exploration journalist and the editor of The Scuttlefish and The Wirecutter. He is a Gizmodo alum and a Wired Magazine contributor. Videos provided by One World One Ocean, a campaign dedicated to telling the story of the ocean through multimedia.