Snorkel the gap between two continents in water you can drink.
Double Fathom ranking
The wildcard
A one-in-the-world snorkel in a glacier-fed fissure between two tectonic plates — with visibility reported at over 100 metres, in water so pure you can drink it. Not a reef trip: a geological wonder that belongs on a cold-water bucket list.
The distinctive underwater sights worth planning around. Descriptions are curated planning info — always verify local access, rules and conditions before you set out.
📍 Thingvellir National Park, Iceland
The grand, boulder-walled section of the fissure where you drift between the North American and Eurasian plates. Glacial melt filtered through lava gives phenomenal visibility and an electric-blue glow.
Always snorkel with a certified guided group — it's a glacial-fed, very cold fissure requiring a drysuit.
📍 The wider cavern mid-fissure
The fissure opens into a broad underwater hall of clear, drinkable water — a surreal, cathedral-like space with extraordinary light and near-infinite visibility.
📍 At the fissure's outlet, Thingvellir
The calm lagoon where the fissure empties — and the whole dramatic rift-valley setting above water, a UNESCO World Heritage landscape you can walk before getting in.
Eat like a local — three off-the-radar spots to round out a day in the water. Spots above the tourist strip, found by asking where the boat crews and neighbours actually eat.
Laugarvatn / the geothermal lakes, south Iceland
A geothermal bakery buries its rye bread (rúgbrauð) in the steaming earth for hours until it turns a dark, sweet slab, then serves it warm with butter and smoked lamb beside the hot springs. Pure Iceland, and a lovely warm-up after Silfra's near-freezing water.
Tip: Pair the bread with hangikjöt (smoked lamb) and plenty of butter.
The countryside around Selfoss / Þingvellir
A working farm café down a dirt road serves hearty kjötsúpa — Icelandic lamb soup — and freshly baked flatkaka with smoked trout, to a room of farmers and a few lucky travellers. The lamb is from the fields you can see.
Tip: Order the lamb soup, then ask for skyr with it for a proper local finish.
A Reykjavík neighbourhood, away from the downtown landmarks
Skip the famous downtown hot-dog stand and find the one the office workers queue at on the way home — the same Icelandic pylsa with its crispy onions, remoulade and sweet mustard, minus the crowds. A steaming, absurdly satisfying end to a cold-water day.
Tip: Order it 'eina með öllu' — one with everything — for the full experience.
Planning Silfra?
Get the whole journey built end-to-end — flights, stays, boat days, gear and day-by-day timing notes — by the Double Fathom Concierge for a one-time $29. Re-plan any time, chat support through the trip, a destination-specific packing list, curated off-menu operators, and a printable offline PDF itinerary.
Secure checkout by Stripe — pay by card, receipt by email. A one-time, per-trip purchase — nothing recurring, and no rush either way.
The free Mission Briefing is one fixed Raja Ampat sample — not a custom build. To have this destination planned properly, the $29 Concierge tier plans around your dates and re-plans as often as you like.