X-RAY MAG: What was your first diving experience and what got you interested in diving?

JB: I’ve always been a keen diver since I was a boy. Living close to the water, snorkeling and water sports has always been a natural part of my life. Sport diving was never a big thing for me. I spent more time as a freediver and an underwater rugby player. My real passion for diving started when I became involved in the development of the Poseidon MKVI.

I want to give divers the time to think before they act, based on the huge task load under water. But primarily it is the underwater experience that is the key for future innovation.

— Jonas Brandt

It was in autumn 2010 that my colleague, Sergey Gorpinyuk, proposed the original idea to me: to dive a distance of 7km. As to a location for the experiment, we chose the colorful Mexican cenotes (caves) because they have long passages, calm current and stable direction. In addition, they have markup distances and many exits. We needed only to mark the way in the caves with guidelines. The rebreather was chosen as a technical means for the realization of the project.

 

However, despite their increased capabilities, rebreathers can be subject to serious failures. Accordingly, one of the primary objectives of good rebreather training is to learn how to react correctly and quickly to a problem and perform the emergency procedure appropriate to the situation or the failure.

Coming up first on the agenda was taking a closer look at the innards and getting familiar with all the components and how they came together. Looking at the unit as it was laid out gutted on the table, it struck me how compact everything was. The breathing hoses, for example, of which there are four short identical ones, are each just about a foot long.

In the old days of the German colony (1890-1915), the farmers of the north-east would draw water from these sinkholes, with electric pumps, for their cattle and in order to irrigate their farms. A hundred thousand years ago, San or Bushmen knew about their existence, too, for they gave names to these natural pits. Somehow, these inspired fear. The belief was that, whoever fell in would not come out alive!

It’s the silence that first catches the attention, as you descend in the water column. There are no noisy bubbles. You can hear the soft whisper and rhythm of your own breathing and almost detect the beat of your heart. You relax and slow down. Often divers don’t notice that they are breathing warm moist “air” (actually a dynamic mix of nitrox or heliox) until sometime later in the dive. You feel warmer in comparison to scuba and not dehydrated.

 

If, at first, you don’t succeed...

Rebreathers are not new: the concept dates back several centuries and they have been used by military and commercial divers for over a hundred years.

 

The notion of sport divers using rebreathers is not new either. In the 1960s Italian and American companies developed rebreathers for public sale but a series of accidents and training agency bans ensured that these experiments were short-lived and dissuaded others from attempting similar ventures for 25 years or so.

 

For example, the same first rule is true for technical diving. Gas management 101 starts off by stating something like: “Always have a sufficient volume of appropriate gas to breathe throughout the whole dive!”

Ojamo lime mine is situated 60 kilometers west of Helsinki. It attracts thousands of visitors every year. The mine area is part of the city of Lohja, known for its industry.

The mining operations began here in the 19th century. When the open pit got too deep, mining was taken into the tunnels. More technology was introduced to boost the human powered operations. Ojamo mine was a key driver of development for the area for decades. It fuelled the local economy and provided work for the locals.

A rebreather is simply a way to reuse the gas breathed out by the diver in conjunction with a method of removing the carbon dioxide produced by the diver. The main advantage of a rebreather is that it is much more efficient on gas usage. When breathing normal air at the surface, we use up about 4% of the oxygen in the air for our metabolism and breathe out the rest of the oxygen as well as all the nitrogen.