The world's strongest maelstrom
Saltstraumen is created when the tide flows into and out of Skjerstadfjord. Sea level height difference between the inside and outside of the narrow strait can be almost one meter (three feet). To equalize the difference tidal waters are pushed four times a day with great speed through the three kilometers long and only 150 meters wide strait. Estimates suggest that 372 to 400 million cubic meters of water is forced through the strait each time.
The average speed of Saltstraumen is around 7 knots (about 13 km/h) but the maximum speed is much higher – Saltstraumen can achieve a speed of about 20 knots. Like all tidal currents Saltstraumen is the strongest just after new and full moon.
Important information if you want to visit Saltstraumen
It is also important to note that Saltstraumen table shows the time when the current is flowing in or out the strongest, while the tide chart shows the time when it's a high tide or a low tide. Between these two times there is about 3 hours time difference (between the tides and the maximum of the Saltstraumen). This delay is due to throttling of the tide. Narrow inlets of fjords result in significant delay of the tide inside of the fjord and on the sea outside. The height difference between high and low tides is also much smaller inside of the fjord. The reason for this is that the fjord doesn’t have enough time to be filled or emptied through the narrow inlet during the six hours between tides of the sea outside.
This phenomenon is called “tidal choking." Throttling can be observed in many fjords with narrow inlet. Saltstraumen pushes tides into the Skjerstadfjord with 2 hours delay to tides times.
Rich world of fish and plants
In Saltstraumen you can find large quantities of cod, pollock, halibut, monkfish and wolffish. Cod and catfish are common catches for anglers, and there are large numbers of seabirds that spend winters and feed on fish here. The reason for this large diversity of fauna and flora is the maelstrom that adds oxygen to the water and carries nutrients that plants and fish benefit from. Eiders and eagles are found in the vicinity. Saltstraumen is recognized as a marine conservation area and has been selected as one of The Wild Wonders of Europe by National Geographic and WWF. Sport divers also found a small coral reef just outside of the current.