The Jakobsens underwater in the LULA1000 submersible

© Stiftung Rebikoff-Niggeler

Passion for the deep sea

Kirsten and Joachim Jakobsen are completely at home under water: Equipped with a viewing dome made of PLEXIGLAS®, the married couple explores the deep sea and its inhabitants in the LULA1000 submersible.

Joachim Jakobsen started diving when he was just five years old. Today, he and his wife Kirsten explore the deep sea. Since 2013, the couple have been looking for the legendary giant squid. However, they have not yet found the Architeuthis. The previous lack of success has not put the researchers off their quest though. On the contrary, they want to track down the underwater giant with the help of a new strategy. In the following interview, the Jakobsens explain what their exact plan is and how the only way to succeed depends on the LULA1000 with PLEXIGLAS® viewing dome.

Kirsten and Joachim Jakobsen

Researchers with a passion

The Jakobsens have been exploring the underwater world together for many years. They are on the lookout for lost submarines and deep sea creatures. In 1994, the couple founded the Rebikoff-Niggeler Foundation non-profit organization on the island of Faial in the Azores. This organization helps them continue the work of the underwater pioneers, Dimitri Rebikoff and Ada Rebifkoff-Niggeler. In order to better understand the habitat of the deep sea, the couple take their LULA1000 submersible to depths of up to 1,000 meters.

© Christoph Bauer / Röhm GmbH

Mr. Jakobsen, when did you have the idea to build a submersible?

Joachim Jakobsen: I know it sounds strange but, as a young boy, I was on a trip with my parents through the Eifel and I saw a slurry tanker, which is basically a pressurized container with an entry on the top. And I thought to myself, if you put a PLEXIGLAS® window on the front of that, it could be a submersible!

The PLEXIGLAS® dome in the LULA1000

For the viewing dome of the LULA1000, an approx. 1,000 kilogram block of PLEXIGLAS® was shaped. The curved shape of the dome allows a 150° view. At depths of 1,000 meters, the pressure reaches 1,000 tons per square meter. Glass would not be capable of withstanding these extreme conditions. The PLEXIGLAS® sheets were processed by the experts at Heinz Fritz Kunststoffverarbeitung who created the high-quality surface of the dome by sanding and polishing it.

An ambitious plan for a young child.

Joachim Jakobsen: I grew up around submersibles. My father worked for the diving pioneers Dimitri Rebikoff and Ada Rebifkoff-Niggeler. Diving was part of daily life. I got my first piece of diving equipment when I was five and I used it to look for Easter eggs underwater.

There’s quite a jump between diving for Easter eggs and deep sea diving.

Joachim Jakobsen: True. But there was a step in between. Before LULA1000 came LULA500. It had a different concept, using a diesel engine for propulsion above water. However, it had a viewing dome which didn’t meet our requirements and was only good for diving to depths of 500 meters. It soon became clear that LULA1000 had to have a dome made of highly transparent and extremely strong PLEXIGLAS®.

It was clear to us that LULA100 had to have a dome made of highly transparent PLEXIGLAS®.

Joachim Jakobsen

So, in 2010, you approached Röhm with your idea. How did the manufacturer of the brand acrylic glass react to your request?

Joachim Jakobsen: At first, they were astonished. The thick, perfect blocks have been produced in Weiterstadt for a quite some time. But forming a viewing dome shape from PLEXIGLAS® was unknown territory for the company. Wolfgang Stuber was my contact and he recommended I look for an alternative, just in case. But I was stubborn. I wanted PLEXIGLAS® to fulfill our high optical requirements and nothing else.

Mrs. Jakobsen, you are the camerawoman of the deep sea. Has your husband’s persistence paid off?

Kirsten Jakobsen: Absolutely! The first time we dived in the LULA1000, we saw the viewing dome disappear in front of our eyes and our camera – an amazing effect. It just simply disappears! Almost all of our guests have asked if they can touch the dome, just to check if it is still there.

The first time we dived in the LULA1000, we saw the viewing dome disappear in front of our eyes and our camera – an amazing effect.

Kirsten Jakobsen

But you haven’t yet been able to film the giant squid?

Kirsten Jakobsen: Unfortunately no, but we will. Filming animals requires patience and perfect equipment to be ready when the time comes. We have filmed many, many other animals underwater though, including minuscule creatures, whose images are also razor-sharp thanks to the clarity afforded to us by the dome.

Joachim Jakobsen: And this is exactly what excites the scientists who dive with us so much. They are only a few meters away from animals in their natural environment which they would otherwise only be able to see dead in their laboratories, if at all.

You also found a lost submarine. Are you still looking for the giant squid?

Kirsten Jakobsen: Definitely. We are now working together with a team of German scientists who specialize in whales. For the first time, we will be spending several days at sea with our submersible carrier and the LULA1000.

Why whales?

Joachim Jakobsen: Squids are a sperm whale’s favorite food. And their absolute favorite is the giant squid. We want to use the hunting ability of this giant to get closer to our goal of filming an Architeuthis.

Read more on submersibles with viewing domes made from PLEXIGLAS®: 

The LULA1000 on the lookout for the giant squid
LULA1000 discovers a missing German submarine
Triton Submarines: Luxury in the deep sea
Diving down to the Great Barrier Reef 
Anglerfish: Sensational video from the deep sea