Dive Site Review: Strýtan Hydrothermal Vent, Iceland

Strýtan is a hydrothermal vent located in the North Atlantic at a depth of 16–65 meters (50 –230 ft). It is situated within the most northern fjord in Iceland, Eyjafjörður near Akureyri.

Unique Features and Topography

Strýtan is a hydrothermal vent where hot fresh water from underneath the seabed is pumped into the cold salt water. Over the 10,000 years that the vent has been emitting this hot fresh water, it has built up a cone of mineral deposits that extends from 65 meters (230 ft) at the bottom of the sea to just 15 meters (50 feet) from the surface. The water comes out at a temperature of 79°C (169°F) and then mixes with the cold salt water, creating both a halocline and thermocline that are visible to divers.

Only in 1997 was the Strýtan vent field reported by divers Erlendur Bogason and Árni Halldósson when it was identified as a real geologic feature. Since its discovery, it has become a popular dive site in Iceland due to being one of the shallowest vents known on earth. Big Strýtan is the famous cone, but a second site called Arnarnesstrýtur (sometimes referred to as Little Strýtan) is also diveable. Both sites offer excellent diving, with the smaller chimney known for its incredible marine life. The mix of hot fresh water and cold salt water has been studied by many international agencies and scientists, including NASA, as it is seen to be a unique opportunity for research.

Marine Life

Arnarnesstrýtur is famous for the abundance of Atlantic wolffish that reside there all year round and are monitored and studied by local diver Erlendur Bogason. In addition to the wolffish, lumpfish and cod are often seen at the site, especially in the summer months. During these summer months the breeding behaviors of both wolffish and lumpfish can be observed. The peak of the wolffish breeding season is in August, and lumpfish can be seen guarding their eggs from May onwards.

Strýtan itself has an abundance of mussels, bryozoans, sponges, hydroids, brittlestars, and polychaete worms, along with anemones and nudibranchs that come in a variety of different colors. Sometimes schools of pollack can also be found in the water surrounding the chimney. The dive site is more famous for its geological formations and haloclines and thermoclines.

Diving Conditions and Accessibility

Arnarnesstrýtur is the easier of the two dives, and usually both sites are dived as a one-day package: Arnarnesstrýtur in the morning followed by Strýtan for the second dive. Arnarnesstrýtur has a permanent line which descends to the ocean floor at a depth of 20 meters (66 feet). From there, it’s a small dive site as the wolffish will immediately come to you when you get close to the bottom.

Strýtan is a more challenging dive. A line from the surface takes you to 25 meters (82 feet), where a second horizontal line then runs you across to the chimney; this is to preserve the cone. Once you reach the cone, you spiral your way up to the top of it at 15 meters (50 feet). Great buoyancy is essential as the seabed lies at 65 meters (230 feet) and the cone is very fragile; touching it will cause immediate damage. Both dive sites can have visibility ranging from 3 to 10 meters (10 - 33 feet) and are both cold water dive sites with temperatures ranging from 2 degrees C (35.6F) in winter to 6C (42.8F) in the summer. Drysuits are essential and a lot of drysuit experience is mandatory for diving here. These are not dive sites for people who are not very comfortable in these conditions.

Why You Should Dive Here

Both dive sites are incredibly unique. One offers marine life sightings that you are unlikely to find anywhere else on earth, with an abundance of wolffish that are also diver-friendly and free-swimming. The larger cone is a once-in-a-lifetime dive site; there is nowhere else on earth where you can dive a hydrothermal cone at recreational dive limits.

Tips for a Great Dive

1. Timing Your Dive: The best dives are in the summer months from May to September for the best weather conditions and to see the breeding cycle of the wolffish as they hibernate through winter until spring.

2. Equipment Check: Appropriate thermal protection is needed, including a well-fitting and well-maintained drysuit. The water here is too cold for leaking suits.

3. Lights: A good light makes for a much better experience diving in these cooler green waters.

How To Get There

A direct flight to Reykjavik is available from all over Europe and almost all major US cities, especially on the East Coast. Upon arrival, you will need to get to North Iceland, which can be done via domestic flight, rental car, or as part of a multi-day dive expedition with a local operator.

Local Operator

Arctic Adventures offers all types of tours and activities in Iceland, including multi-day dive expeditions all over Iceland.

Strýtan Dive center is home to the founder of Strýtan, Erlendur Bogason. All Arctic Adventures tours from Reykjavik will also use the local services of Strýtan Dive center.

Conclusion

Strýtan and Arnarnesstrýtur offer a unique diving experience that combines geological wonder with rich marine life. These sites provide not only an adventure for experienced divers but also an opportunity to witness rare natural phenomena and contribute to scientific research. Diving here promises an unforgettable encounter with nature's underwater marvels, making it a must-visit for dedicated divers.