Considering Iceland’s high latitude just outside the Arctic Circle, it has a temperate climate due to the warming effect of the Gulf Stream, but diving in Iceland is strictly dry suit all year round. I was drawn to diving in Iceland because of its natural beauty and because it has so many unique diving sites, I have done some but not all on this trip.
Kleifarvatn is the largest lake on the Reykjanes peninsula, the deepest part is around 97m deep and lies around 1000 meters above sea level. Although only 35 minutes from Reykjavik, the location feels totally remote. You drive up via volcanic tracks and an impressive and mysterious volcanic landscape, full of high and amazingly coloured hills and lava formations. In the year 2000 after a large earthquake, a fissure appeared and the lake lost around 20% of its water into the bowels of the earth. At that time if you put your ear to the ground you could hear the water draining from the lake, as if it were disappearing down a plughole. In 2000 the lake measured about 3.7 miles in length and 1.4 miles in width and it subsequently shrunk dramatically to approximately 2.2 miles by 1.2 miles wide. It has since filled to its old levels.
Just before we dived and at a slightly higher elevation we visited another hot spot, where we witnessed first hand the geology of the terrain we would be diving over. The lake has several hot spots that are spewing among other gases and minerals copious amounts of Sulphur Dioxide into the lake, these hot spots have only been discovered a few years ago by geologists studying the area. On the day of our dive there was quite a strong current, the hot spot we dived which is fairly near to the shore of the lake was not that large in area, measuring around 200m x 100m with an average depth of around 16m. It had one large crater which was quite deeper than the surrounding terrain where the main gasses where emanating from. You can see the mineral deposits on the lake bed and the fields of bubbles. The veracity in activity depends on the prevailing seismic conditions. The water temperature on the day was 4˚C.
Garður is located at the end of the Reykjanes peninsula, about an hour’s drive south of Reykjavík and part of the North Atlantic Ocean. Garður means garden in Icelandic and it does indeed contain a bountiful garden of over 42 species of marine algae. The site we dived had an impressive kelp forest containing a varied marine life, both large and small. There is lots of life, in particular many species of flat fish, Monkfish fish, Lump Suckers, Crab and Wolf Fish. If you’re in to macro photography there is also a lot of Macro opportunities with many species of Nudibranchs. This is a shore dive and on the day of our dive it was low tide, which made getting into the water quite precarious, walking across slippery rocks and pools. Well worth it, although the visibility was not the best on the day. Water temperature was 8˚C.
Diving in Iceland on Lake Kleifarvatn, Gardur & The Silfra Fissure
The main reason for my visit to Iceland and Iceland’s most popular site for diving. Although it’s all subjective, it has been voted by many dive publications and professionals to be one of the top 10 world dive sites. In my 160 plus dives to date of which many of you would have seen the places and the marine life that I have dived with, it is up there as my top dive.
Silfra is a fissure located by the Þingvallavatn Lake in the Thingvellir National Park. The park is a UNESCO World Heritage site both for its cultural and historical significance as well as natural and geological uniqueness. The fissure is a rift that is part of the divergent tectonic boundary between the North American and Eurasian plates, separating at Silfra on average at a rate of 2cm per year.
The Mid-Atlantic Ridge is part of the longest mountain range in the world, which for the most part lies beneath the Atlantic Ocean, running from North-East Greenland all the way down to the South Atlantic over a distance of 65.000km. The majority of the peak of the ridge line lies at 2,500m below sea-level, but there are areas where it rises so high that it reaches above the surface and creates islands, such as the Azores and Iceland. Silfra is the only point where you can dive and touch both continents.
The water at Silfra is fed from Iceland's second largest glacier Lángjökull, its melt water trickles underground through porous lava rock. From its inception at the glacier, it takes a drop of water between 30 and 100 years to travel the 50 kilometres to the Þingvallavatn Lake and it all has to go through Silfra. As it travels the water is filtered by the volcanic rock and is so pure by the time it gets to Silfra you can actually drink it. The water is so crystal clear that light is not broken up by the water surface and bounces back so that you get total internal reflection, as can be seen on some of the photographs.
The main Silfra fissure is approximately 300m long with an additional 100m or so extending out into Þingvallavatn Lake. There are many tunnels and caverns that form Silfra, the deepest being 63 meters deep. However, due to the instability of the rock from daily seismic activity and frequent earthquakes it is strictly forbidden by law to dive these tunnels. This is due to the high risk of loose rocks and collapses.
The first of the five sections of Silfra that divers have access to is known as the Big Crack. This section is 120m long and holds the deepest area of the main fissure. The first part of the fissure drops to 23m before it heads down under the rocks to a maximum depth of 45m.
The second section is known as Silfra Hall. This is where the fissure first widens out and opens into an area 10m deep, 50m long and about 8m wide. The bottom here is littered with boulders half the size of cars. These boulders and the rocks that litter Silfra have been deposited as a result of the many earthquakes and constant seismic activity aroun teh Mid-Altantic Ridge that continually causes the break up of the walls along the tectonic plates. Silfra hall then leads onto the Cathedral, which is a truly awe-inspiring sight. At 100m in length, 20m in depth and with walls that run to within 30cm of the surface, it is possible to see all the way to the end, proving the visibility of over 100m, the longest recorded visibility anywhere in the world. Due to these wall sections the dive profile is not the best, so the guides generally like to limit the maximum dive depth to 18m.
At the end of The Cathedral is one of the most dangerous spots for divers as the up-welling of the current to a depth of 2-3m tries to push you out into the main lake, so it is important to make a timely left hand turn and enter into the penultimate section Silfra Lagoon. Silfra Lagoon offers dramatic views with visibility stretching to 120m. With a shallow sandy bottom, the water in the Lagoon takes on a more turquoise colour. You can swim the length of the Lagoon to get to an exit platform, or you can explore further and head off to the left hand side to discover the final section of Silfra called Little Crack. The temperature of the water was 2˚C on the day.
A truly awe inspiring dive, that if you can, you should attempt at least once in your lifetime. It will forever be in my memory.