These divers are gearing up to head 400 feet underwater.
Their bodies will experience immense, almost fatal, pressure that can literally turn the
very thing keeping them alive — against them.
“The longer you stay down there, the more gas, mostly helium, also nitrogen, on boards
into your tissues, into your blood, into your muscles, into your bones; it’s just building
up inside your body and you have to let that out.”
The Twilight Zone is one of the most mysterious and dangerous places on Earth.
Only an elite team can handle the complexities of diving at these depths and conduct scientific
research.
Their job is a race against time to survey these deepwater coral before they come under
serious threat from pollution and warming ocean temperatures.
“I would say less than 10, 15 scientists worldwide go to those depths.
And because of that, everything is new.
Everything is novel.
We don't know what's there, because nobody goes there.”
Luiz Rocha is one of only a dozen of divers in the world with enough expertise to reach
the twilight zone.
A place you don’t want to visit alone.
“We're dive buddies, so Luiz and I, we’re almost inseparable, both on land and underwater.”
Bart and Luiz are equipped with nearly 180 pounds of gear.
Fins, bailout tanks, propeller scooters, and dive computers — these are all essential
to surviving in the twilight zone.
“Getting all the gear on, on the boat, and getting ready to drop into the water is definitely
the most intense time.
We make sure our straps are all clipped, we make sure our valves are on.
It's hot, you're in the sun, in Neoprene, black, dying basically.”
The key piece of equipment that will keep Bart and Luiz alive is called the rebreather.
Because at the levels they're going, the normal mix of oxygen and nitrogen actually becomes
toxic.
“The deeper we go with nitrogen, the more narcotic it becomes.
So it's the equivalent of diving drunk.”
“We make the sign to descent and we go down together.
That can be a 300 foot free fall.”
“When you're in a shallow tropical coral reef it's well lit, it's warm, and as we go
deeper we see the transition.
Everything becomes slower, and colder, and darker.”
“Then finally you'll start to see the bottom come up and that's when you work.
You have your 10 minutes, your 15 minutes on the bottom.”
And that’s it.
That’s all the time that these divers can spend exploring the Twilight Zone before all
that gas they’re inhaling becomes lethal.
“It requires constantly monitoring yourself for symptoms of all kinds of different aspects
of different gases interacting with your body.
So we have to be constantly thinking about our gear and ourselves, and at the same time,
trying to do science at those depths.”
During their incredibly short window of time, the dive team have to survey their surroundings,
catalogue coral and capture new species.
In fact, they’ve been known to collect 12 new species in just a single dive.
“It's really intense.
All you're thinking about is, "Catch the fish.
Do the job that I'm here to do.
Where's my buddy?
Okay, everybody's okay.
What's the time?
OK I’ve got a little bit more time.”
“We have our own language and screaming gestures, and taglines, and things like that
that we'll use to communicate and then we'll scream at each other in our ridiculous helium
voices if we see something really exciting, you know, come over here and look at this
fish.”
Bart and Luiz would spend hours down in the Twilight Zone if they could, but it's time
to ascend.
“We have an agreed upon time where we leave, what we call the TTS, the Time To Surface.”
Ascending too fast can cause life threatening conditions, like decompression sickness or
the bends.
So Luiz and Bart follow a very specific decompression schedule, which means ascending in stages.
“If we have 10 to 15 minutes at the bottom, it could be 3-4 hours after that to come back
up to the surface.”
The longest stop is just before Bart and Luiz surface - just 10 ft below the waterline where
they can spend up to 90 minutes.
90 minutes in just one spot.
“I’ve had about 300 hours of rebreather diving now in the past few years doing this
project, and when you think about it, it's probably like maybe a sixth of that is in
the Twilight Zone and the rest of it's all the decompression.
But you know, it's worth it.”
Bart and Luiz are just beginning to scratch the surface of the Twilight Zone.
And the information they collect from these deep reefs are invaluable.
They’re so rarely studied, that we could be in danger of losing them before we fully
understand them.
“Every time we go to those depths, We find plastics, we find fishing gear//We find all
signs of human activity, even as deep as we go, to 400, 500 feet.”
And Bart and Luiz are willing to go through the process of donning heavy equipment, risking
decompression sickness and spending hours underwater, over and over again, just so they
can better understand this world.
“It's definitely worth it to be able to go down there and see places that no person
has ever seen before.”