IN THE SPRING OF 2013 I bought my first underwater camera, and I haven’t looked back. I’ve had great fun using it, but admit to slow progress and varied levels of success.
As a child, I remember hearing stories of a place where you could walk down a valley between the continental shelves of Eurasia and the Americas as they crept further apart. It took years to discover the even-better part – as it turns out, you can dive there, too.
A handful of days at the end of a busy summer spent galloping from one airsports event to the next was all the time I really had to myself in 2014.
The combination of an offer from one of my skydiving students to add my name to the staff-list of a popular orangey budget airline, and a quick session of deductive filtering through a long list of European cities, saw me booked on a flight to Iceland’s capital Reykjavik.
A hasty airport-transfer conversation in Amsterdam about the world and its offerings led the research for my trip towards the Silfra Fissure.
It had been a while since I had been under water, thanks to an altered situation and location, and my life had become filled for the most part with parachutes. I had never taken my eye off diving, however, and every now and then one can feel the universe lining things up for you.
As I headed out of Reykjavik in the direction of Thingvellir National Park, the thermometer in my tiny rental car displayed a flat zero.
Thingvellir, as well as being eerily, resoundingly beautiful, is Iceland’s place of greatest historical significance.
It was there that Iceland took the first formative steps toward becoming the impeccably civilised country it is today (which, as far as I have learned, meant its founders taking turns to talk while standing on a big rock).
I’m convinced that they picked this spot because of the long line of cliffs that shoulder the area. These provide some respite from the kind of wind that car-rental companies fear – they offer special insurance against its ability to tear the doors off small vehicles when they are opened excitedly in an exposed car park at some jaw-dropping natural wonder or other.
Iceland has a small population, most of whom live in the capital. Just a few miles out of the city the snowy road has clear tracks in just one direction, carved out by the daily procession of tourist transport heading the same way, to a popular sequence of awe-inspiring geological phenomena.
Some of the heavily modified off-road vehicles that cart the tourists about are gigantic. They look like the sort of thing I would have drawn when I was 10, down to the cartoonishly enormous tyres.
I worried less about the fierce wind trying to slide me off the road than I did about having to swerve to avoid one of these vehicles, and end up careening down the steep slopes at the side of the highway into the frosty tundra.
I feared that my miniature VW’s sole concession to the conditions – the chunky tread of a set of winter tyres – would not help much if I was pancaked by a Land Cruiser the size of a house.
I had chosen a day on the booking system that looked quiet, and indeed there was only one other diver.
Our guide was Chris, an Englishman, though I had assumed he was Australian, as all his sentences ended in an upward inflection. That, however, can be the way with guides required to shepherd groups of strangers through an unfamiliar and possibly stressful activity day after day.
Chris reeled off the information we needed in a manner that showed that he had done this many times, but he was friendly and good at his job. As someone who has performed a similar function in a very different environment, I value this kind of no-fuss efficiency.
Despite the gap in my diving history I am quite well qualified (as was Matt from Tasmania) so Chris dispensed with the fluff and let us get on with it.

WE LINGERED TO GIVE OURSELVES a little space between the groups. Apprehensive- looking tourists waddled past like lines of ducklings behind their guides to snorkel the same route, not sure that this was what they wanted to be doing that day.
The steps into the water, complete with inch-thick ice, are very close to the point where the diverging land-masses initially cracked. The crack let in the fresh water that made it here through mile after mile of volcanic rock, filtering and purifying it to as good an example of perfection as I have to share.
A short distance from the start of the route is a separate pool where it is possible to access the network of caves.
This pool links to the start of the Silfra Route via an opening creatively titled Toilet – named for its ability to flush divers head-first down a 30m tunnel and out into the first part of the more sensible Silfra Hall.
The cave system here has been mapped to 63m by a US team, but with the regular seismic activity it is highly likely that the topography has altered since then.
These factors mean that overhead adventuring here is reserved for the gnarliest of explorers.
Having participated in some medium-strength penetration dives (and as someone who counts BASE-jumping high on his list of hobbies) I always shudder when I think of cave-diving.
Silfra Hall is the first section of the route that we have been briefed to think of as deep-shallow-deep-shallow. It’s here that the separating land-masses remain close enough to allow a diver to lay a hand on either side.
This is the only place where it is possible to do this on the entire Mid-Atlantic ridge – a geological enormity that runs almost the entire length of the ocean from Greenland to Antarctica.
It creates a  bit of a bottleneck of divers as one after another we dutifully assume the position for a photo while touching both continental shelves.
The shallow sections of the dive are created in places where very frequent (in geological terms) upheavals have piled up loose rock shorn from the walls or deposited from above. It’s a little like climbing over a mound of rubble, so care is required to negotiate a path.

SILFRA CATHEDRAL, the second deep section of the route, is as good a place as any in which to worship the majesty of the natural world as you swim its 100m length. While the canyon is not what some would consider deep – 20m here and there but averaging around 12m – the combination of the close walls and the clarity of the water instils in you a sense of great scale, especially from close to the surface.
It is not unknown every once in a while for an unsuspecting snorkeller to abandon the whole thing, based on a sudden vertigo-induced panic attack.
The water is so clear that eyes and brain are unable to process that it is holding you up above the rocks below.
This part is everything I could ask for from a scenic dive, and well worth the effort and admission price on its own.
The spring at the head of the fissure creates some small current through Silfra, but it is only really noticeable along the second shallow section of the dive, where the water from the voluminous Cathedral pushes and squeezes through, trying gently but firmly to carry you with it out into the lake, instead of making the left turn into the final area of the route.
Silfra Lagoon is the aptly named finale – a huge shallow bowl with gently sloping sides that offers up its own comforting version of beauty in contrast to the drama of what has come before.
There are fish in the lake, but here they are little more than a rumour – yet the absence of life seems to attune your senses to the scenery all the more.
Again the clarity is bewildering, with all you can see across the Lagoon’s 120m diameter remaining pin-sharp.

I AM JUST OVER 6ft 6in. As a result of my enormousness, rental gear can be a dicey prospect, but the drysuit provided had not been bad, letting me down only once when I craned my neck a little too far, and felt a small escape of air replaced by an icy trickle to the base of my spine.
The resulting lapse in concentration was the only time I stirred up a cloud of silt from the bottom into what was otherwise the clearest water I have ever seen.
As a small boy at the NASA facility in Houston I stood with my face pressed against the glass of those colossal training pools and watched astronauts practise extra-vehicular activity around the full-scale exterior of a Space Shuttle.
The clarity of the Silfra water reminded me more of those pools than any of the other dives I have done.
When the air temperature drops below freezing at Silfra the operators tend to do one extended dive, because things with moving parts, both mechanical and human, freeze up and become prone to damage or failure.
So we dived for about 45 minutes, lingering in places of particular beauty but with no rush to get through the five named sections of the dive.
The scenery was spectacular. The cobalt-blue water hides nothing from view in the long canyons, so the vista is unobscured as far as you can see in any direction.
My rusty skills meant that I could have used a little more weight, as I needed a bit more air in my suit to avoid the chilliness I felt during the last few minutes.
Don’t be put off by the chance of cold weather limiting your visit to a single dive. We were encouraged to swim at any pace we wished and take as long as energy, air and temperature allowed.
At no point did I feel stiffed out of that second dive.
Whatever wild weather spirits are in charge of this land looked favourably on us, and the sun was out when we surfaced. We trudged happily back to the vehicles for the hot chocolate Chris had brought, and the extra cookies I had asked him to remember.  
Surrounded on every side for hundreds of miles by proper ocean, Iceland has weather. It’s neither nestled among other islands nor tucked in against a continental mass like the UK.
You can look out to the horizon and see the whole menu of systems and fronts lining up against each other.
Sideways snow gives way to sideways hail and then some sideways sunshine, because it is the tail-end of November and the sun doesn’t get much above the horizon. However, it does magnificent things to the clouds and the landscape throughout all six hours of daylight.

ICELAND IS UTTERLY beautiful, as is diving at Silfra. In places the country looks like a sci-fi planetscape from a 1960s fantasy movie, and in others like the waterfall-draped fairy garden from a children’s book.
Somehow it feels more connected to the formation and evolution of the Earth than anywhere else I’ve seen.
A short drive on from Thingvellir takes you to a place where the planet celebrates how awesome it is by every few minutes joyously squirting a lot of hot water high into the air.
If it’s possible for humans to perceive such a thing, you can feel the youth of the planet there.

GETTING THERE EasyJet flies to Keflavik airport, 30 miles south-west of Reykjavik. Silfra is in Thingvellir National Park, about 28 miles north-east.
ACCOMMODATION Joel used to find a budget room in an apartment with Rekyjavik locals.
WHEN TO GO In winter when daylight lasts only a few hours, tour operators offer a mid-morning dive at Silfra. In summer, when the sun barely dips, you can start morning or afternoon.
CURRENCY Icelandic krona.
PRICES Dive Worldwide offers its three-day Silfra Diving Weekend from June-September from £995pp for flights, three nights’ B&B at Center Hotel Plaza (two sharing), two dives at Silfra, dive gear, sightseeing and transfers. Arctic Direct has a six-night Wonders of Iceland deal for £2395 including flights, all transport, seven dives including Silfra, kit rental or 40kg baggage allowance, and sightseeing,