Silfra

別名： Silfra Fissure

Silfra lies at the edge of lake Þingvallavatn in a rift of the Mid-Atlantic Ridge, so a dive here takes you into the gap between the North American and Eurasian plates. Its water starts as meltwater from the Langjökull glacier and seeps through porous lava for decades before it emerges, which explains its exceptional clarity and why divers may even drink it. The route runs through the Big Crack, Silfra Hall and the Silfra Cathedral, deep canyons whose floors fall away into caves, and ends in the shallow Silfra Lagoon with its fields of bright green algae. Caves and overhead areas are closed and the depth limit is 18 m, so a typical dive stays around 7 to 12 m for 30 to 45 minutes. Life is sparse but special: an amphipod found only in this lake system, dwarf char all year and Arctic char in late summer.