Snorkeling Silfra Iceland: Between Tectonic Plates

Last Updated on December 13, 2021

One of the best things to do in Iceland is snorkeling Silfra Iceland. It’s the ultimate adventure experience that cannot rival anything else on the island.

Dressed in a bulky dry suit, airtight hood and gloves, I’m taking the plunge into the glacial waters of a narrow crack. It’s not just any crack though – this is literally an opening in the Earth’s crust, a rift that separates two continents, a valley in no man’s land.  I float around in the 2 degrees Celsius water and dip my head beneath the water surface.

It’s a whole new world: sunlight pierces through the crystal-clear water, giant boulders stack atop one another into the endless depth while lime-green algae sway lifelessly in the still waters. Just before our group of snorkelers meander through the rift valley, our guide Hössi says, “Remember where you are, on your right is America,” he pauses for effect, “on your left, Europe.”

Snorkeling Silfra Iceland

We are snorkeling in Silfra, a rift valley between the North American and Eurasian tectonic plates. It cuts through the Thingvellir National Park of Southwestern Iceland – a volcanic area created by the movements of the Earth’s crust. Today, it’s one of the most visited attractions of Iceland, although its rift valley is still a well-kept secret. Diving here first started in 1997 by the Sport Diving School of Iceland in 2007, attracting over 1,000 divers per year.

“Swimming in this rift valley is truly a privilege, you almost feel like you belong to an exclusive club after diving Silfra.” Kevin, an experienced marine archaeologist and dive master at Dive.is explains. Considered one of the best dive sites in the world, Silfra promises visibility of over 100m (in clear glacial waters fit for drinking) and an underwater environment found nowhere else. 

As clear as the water may be, it is after all fed from a glacier and thus stays at a humble temperature of around 2 degrees Celsius even in summer. At this temperature, no marine life can survive (except us humans). This explains why we are all wrapped from head to toe in ultra-protective dry suits and equipment. The preparation earlier that day had taken over one hour – first squeezing into the airtight dry suits, then zipping each other up and ensuring no holes for water to sip through before finally fitting on our gloves, hood, fins and last of all, our snorkel masks. 

Underwater Mystery of Silfra

Back in the Silfra rift valley, we continue to drift along the narrow channel flanked by massive squared boulders. Observing the spillage of rocks and boulders all around me, I let my imagination run wild as I picture how the Earth shook and rattled one day, causing catastrophic eruptions and quakes to form a crack as deep as this.

Each year, this rift expands by 2-3mm as tectonic movements form new Earth. Staring down into the depths of the split, I wonder how it is to be scuba-diving amidst the caves and exploring its hard-to-reach gaps between the boulders.

I’d initially signed up for a dive, but as bookings were full, I opted to snorkel instead. My instructors had assured me that the experience would be equally rewarding – now that I’m floating in the glacial waters of Silfra, I get what he means. The visibility is so good that you don’t need to plunge deep to take in this amazing environment.

While diving brings you deeper into the rift and close to the action, divers are only allowed to go to a maximum depth of 12-15m to assure safety. A recent fatal accident was a result of negligence as a pair of American divers went as deep as 63m and eventually got stuck in a cave. One of them was lost in the depths and by the time the authorities found him, it was too late…

Unique Creations of Nature

In the still waters, there is complete silence – even the usual breathing sounds from my oxygen tank is absent. Drifting through the narrow waterway, we come to a steep slope that leads the channel towards a shallow lagoon. Popping our heads up, we hear Hössi explain, “This site is named ‘the Cathedral’, for the similarity in shape and formation.”  Swimming past it, I turn around and take a good look at the water way – its lofty spaces surrounded by wide and tall walls of rocks is clearly a work of nature, and perhaps spirits of a different kind.

Soon after, we get to a shallow natural pool shimmering in a ridiculous shade of aqua blue. “This is the REAL Blue Lagoon, just take a look and you’ll know what I mean.”  The big boulders are gone, only to be replaced by a marshy bed of rocks and patches of beige wispy algae, around us was an immense blanket of blue. As how Kevin described it earlier, the lagoon resembles scenes straight out of the movie, Avatar.

After spending almost 40 minutes meandering along the rift valley, it’s about time to get back on land. Taking a peek above the water surface, I’m surprised to find the stark contrast in colors: the same patch of land that’s blanketed in lifeless beige algae underwater, explodes into bushes of colorful shrubs on land. This time of the year, Thingvellir blossoms into beautiful autumn colors, although under the water, things stay the same all year round. Nature is truly creative, at times downright bizarre; whatever this case is, I’m definitely ranking Silfra top in my list of favorite works of nature.

Here’s a video shot underwater, it’ll give you a better idea of what goes on at Silfra:

Photos and videos above are courtesy of Dive.is.

This snorkeling trip in Thingvellir was made possible by Dive.is, while my self-drive trip through Iceland was hosted by Discover the World. All opinions expressed above are my own. For more on Iceland, check out my Iceland travel guide.