Cold Water · Norway
Skarnsundet & the Trondheim Fjord
Cold-water coral walls within nitrox range of the surface
Skarnsundet is a tidal strait in the Trondheim Fjord where cold-water corals grow far shallower than they do almost anywhere else. Sea bush appears on current-exposed walls from around 28 m, a bubblegum coral stands at 36 m, and Lophelia grows at Selligrunnen and on the Skarnsundet ridge just beyond. Most dives run from the kelp at 10 m to about 40 m, and closer to Trondheim the fjord holds Second World War wrecks for technical teams.
About diving in Skarnsundet & the Trondheim Fjord
The tide sets the day. The strait carries strong tidal flow, so the site and the departure time are chosen from the tide, current, weather and visibility rather than a fixed schedule. Boats reach sites throughout Skarnsundet and the surrounding fjord system, and more than 30 sites give options for mixed groups. On the Skarnsundet ridge the slack-water window can be as short as 15 minutes. In Trondheim, a dive boat moored on the Nidelva runs to dive sites across the fjord all year.
Below a kelp forest that reaches to about 15 m, the walls of the strait drop through hard bottom, gullies and rock. Yellow sea bush appears from around 28 m alongside sponges, anemones and other filter feeders, and a red bubblegum coral almost a metre across stands at 36 m. More than 50 species of nudibranch have been recorded, including Grieg's tritonia on its host gorgonians, and octopus and squid are regular. Lophelia, the reef builder, grows deeper still, and Tauterryggen is a marine protected area in its own right.
The area suits drysuit divers with good buoyancy and trim who want cold-water corals, and macro and photo divers looking for nudibranchs and small life. Divers newer to drysuits or tidal water can start with a sheltered orientation dive on the house reef. Guided diving stops at 60 m; below that the walls are left to self-sufficient technical teams. Divers who want warm water or a fixed dive schedule should look elsewhere: the water is cold in every month and every plan bends to the tide.
Best time to dive Skarnsundet & the Trondheim Fjord
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Good | Good | Fair | Fair | Fair | Fair | Fair | Fair | Prime | Prime | Good | Good |
Both bases dive through the whole year, choosing sites to suit the weather and the tide rather than the calendar. The coldest water sits near 4 °C, and a drysuit is the standard choice in every month. Spring brings plankton blooms, and by early May the kelp forests are waking up. Blooms can continue through summer, though clearer water lies beneath them. Autumn is the warmest season, with water around 9 to 11 °C (48 to 52 °F), and September and October give the best odds of fine weather and visibility of 9 to 27 m (30 to 90 ft).
Dive types & marine life
Nudibranchs turn up in the kelp and on the walls, octopus and squid are not unusual, and the corals are fixed residents at known depths. After dark, rabbitfish, velvet belly lanternsharks and blackmouth catsharks move into shallower water; none is guaranteed, but night dives raise the odds.
- Wall
- Coral garden
- Kelp forest
- Muck & macro
- Night
- Wreck
- Nudibranchs
- Octopus & cuttlefish
- Squid
Best dive sites in Skarnsundet & the Trondheim Fjord
- 1
Skarnsundet Reef
Lophelia reef at 43 m (140 ft), diveable only twice a day as the tidal current slackens.
- 2
Selligrunnen
Lophelia coral at about 39 m, among the shallowest occurrences of the reef builder on record.
- 3
Tautra Reef
White Lophelia coral spread over about 100 square metres beneath the fjord.
- 4
Consul Carl Fisser
5,900-ton freighter sunk in 1942, upright on a slope from 20 m (65 ft) at the stern to 46 m (150 ft).
- 5
Heinkel HE115 Wrecks
Two wartime seaplanes settled in silt off the Trondheim dock, pitch dark at 44 m (145 ft).
- 6
Småvika House Reef
Sheltered cove reached from shore, steep to about 10 m, then gullies; the night-dive site.
- 7
Garten Island
Kelp forest where the fjord meets the sea, with nudibranch-covered rock at 30 m.
Site guides
Wreck
An upright 5,900-ton wartime freighter sloping from stern to bow
Wreck
Two wartime seaplanes resting in silt beside the Trondheim dock
Deep-sea Lophelia coral growing on a ridge within scuba range
Coral garden
White Lophelia coral over about 100 square metres
Yellow-orange sea fans hosting Grieg's tritonia nudibranchs
How to get to Skarnsundet & the Trondheim Fjord
Trondheim Airport Værnes is the usual arrival, about 1.5 hours by car from the dive centre at Småvika beside the strait. Flybussen links the airport with central Trondheim, where the city dive boat is moored on the Nidelva for trips into the fjord.
Dive videos
Periphylla periphylla/ Coldwaterdiving Norway/Skarnsundet · wargwind on YouTube
Questions divers ask
Can the Skarnsundet corals be seen without technical training?+
Yes. Sea bush grows on the walls from around 28 m and a large bubblegum coral stands at 36 m, both within nitrox range. The Lophelia reef at 43 m (140 ft) is a technical dive.
Is the diving from shore or by boat?+
Both. Boats run to the walls of the strait, timed to the tide, and the house reef beside the centre at Småvika is a shore dive in a sheltered cove, used for orientation and night dives.
When is the best time to dive the Trondheim Fjord?+
September and October, when fine weather is most likely and visibility can reach 27 m (90 ft). Diving continues through the winter, with water near 4 °C.
How is Skarnsundet reached?+
Fly into Trondheim Airport Værnes and drive about 1.5 hours to the centre at Småvika; Flybussen links the airport with central Trondheim for the city boat.
Sources
- Dive Center in Skarnsundet, Norway | Bare Dykk — Bare Dykk
- Diving in Norway – Cold-Water Diving in Skarnsundet — Bare Dykk
- Cold-Water Diving — Bare Dykk
- Dykkerturer - Havsport AS — Havsport AS
- The Dark Side — Scuba Diving
- Trondheim Fjord: A Nordic Diving Adventure Into the Depths — X-Ray Mag
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