Snorkelling in the Reykjanes Peninsula

Kleifarvatn is a deep, moody lake set in a volcanic rift on the Reykjanes Peninsula, and beneath its surface something rare happens: geothermal vents on the lakebed release streams of hot bubbles and shimmering water into the cold, a quiet reminder that you are floating directly on the seam between two continental plates.

Snorkelling here, in a drysuit against the chill, you drift over black volcanic sand watching the vents fizz beneath you, in eerie, otherworldly stillness far quieter and stranger than any reef.

It doesn't have Silfra's fame or its glassy visibility, but it has something few places do: bubbling geothermal activity you can hover above, in a raw rift-valley setting. For the curious, it's a memorable and unusual half-day, and a very Icelandic thing to do.

A guided drysuit snorkel in cold, fresh rift-lake water, drifting over black sand and geothermal vents that bubble up from below. The water is cold year-round, so you're sealed in a drysuit with hood and gloves; guides handle the kit and briefing, and no diving certification is needed.

It's a calm, floating activity rather than a strenuous one — you hover and watch rather than swim hard — but you must be comfortable in cold water with your face submerged.

Visibility is decent but not Silfra-clear, and the appeal is the vents and the surreal rift setting rather than marine life, which is sparse. Weather and lake conditions can affect trips. It's an accessible, unusual introduction to Iceland's geothermal underwater world for confident beginners.

Trips run mainly in the warmer, lighter months, roughly May to September, though the water stays cold throughout.

Go with a guided operator who provides the drysuit, hood, gloves, mask and snorkel and gives a full briefing — this is the safe and easy way in, and no scuba certification is required. You should be a comfortable swimmer and okay with cold water on your face.

Wear warm base layers under the drysuit. Because it's less famous than Silfra, tours are smaller and quieter. Check conditions before booking, as weather can affect visibility and access.

If you want the marquee Icelandic snorkel, that's Silfra in Þingvellir; Kleifarvatn is the offbeat, geothermal alternative for those who want something stranger and less crowded.