Fascination deep sea: Autonomous submarines tap previously unexplored seabed

To this day, the world's oceans and their seabed are largely unexplored.

The conditions on the seabed are too extreme for humans – such as the very high pressure that exists in the depths of the oceans. These extreme circumstances have turned the deep sea to a fascination for mankind up to the present day. Above all, researchers, navies and utilities are interested in exploring the great unknown. The goal: comprehensive mapping of the seabed - a kind of Google Maps for the sea floor.

To provide researchers with these coveted insights, the experts at thyssenkrupp Marine Systems have developed an underwater vehicle that enables unmanned expeditions to the deep sea: the autonomous submarine SeaCat. Marian Marbach, Technical Manager at ATLAS ELEKTRONIK, developed the vehicle together with his team and talked to us about the innovation.

“Very little is yet known about the ocean floor. To humans, it is a hostile environment. Building and sending manned submarines is therefore a very time-consuming and costly process,” the expert explains. “The autonomous world will change this. The use of autonomous underwater vehicles like the SeaCat will make it much easier to collect accurate data from the seabed,” says Marbach.

The reason: manned submarines have to meet high safety standards to protect the crew on board and also require supply components – for example for oxygen supply. “These are all complex components that cost money and space on board,” explains Marian Marbach.

A long breath and stamina for a great task

 The SeaCat is a vehicle of moderate size and can move autonomously under water for up to 18 hours. This represents a significant step forward in the exploration of the seabed. Per dive, the underwater vehicle can literally bring to light a huge amount of data about the deep sea. But how does the SeaCat know what its’ task is? Before the small submarine goes on a dive, it is equipped with a kind of timetable, to put it simply. The SeaCat is therefore programmed in advance for a specific task. The submarine can then perform this task independently down to a depth of 600 metres.

How the SeaCat supports the construction of renewable energy plants

Power generation is not initially an area associated with autonomous underwater vehicles such as the SeaCat. Especially since the SeaCat is primarily used in surveying. However, the autonomous vehicle can provide important information for the construction of intercontinental power and gas lines: For it can analyse water layers, provide information on their composition and the sediments of the sea floor.

The SeaCat can therefore be used to determine which routes on the seabed are most suitable for laying pipelines and pipes. Can the seabed in a particular location be worked at all with the tools available? What are the environmental conditions at that depth and what are the properties that the pipes would need to have in order to survive in that environment?

A blessing for underwater archaeology

“The SeaCat is used in many interesting fields. One of them is underwater archaeology, as in the case of the site in the Arendsee in Saxony-Anhalt,” reports Marian Marbach. In 2003, a sport diver discovered historic boats and unknown construction in the Arendsee.

As it later turned out, evidence of various historical epochs of the Arendsee and its use by humans. Among other things, several late medieval boats and a fish fence for fish farming from the Neolithic period were found. Especially underwater finds, which are partly covered with sediment, are difficult to access. “With its ability to analyse sediment layers, SeaCat was able to make a significant contribution to the development of the finds here”, explains Marbach.

A lot of technology in a small submarine

The mapping of the seabed by the SeaCat is done with sonar data. For example, a high-frequency multi-beam echosounder and a camera mounted on a rotating unit allow detailed mapping of vertical structures. The autonomous boat has extensive technical equipment and customized applications to meet a wide range of requirements.

It remains exciting to see what other secrets are hidden under water. One thing is clear, however: whether it is a business, archaeological or military project, the SeaCat is revolutionizing the work of man under water and will continue to provide us with ever more accurate information about the world under water.