The Nautile is a submarine designed by Ifremer for observation and intervention in ocean depths going down to 6000 meters, which makes 97% of the world's seabed surface accessible.
It can carry different tools or scientific materials for different tasks such as observation, exploration, sampling, expertise, data acquisition or the deployment of scientific tools.
Since its commissioning in 1984, it has dived over 1500 times.
 
For observation and machine maneuvering in deep waters, the Nautile can take 3 people on board. 
 
A few essential differences between the Nautile and a military submarine are apparent:

• the volume of the Nautile is much smaller,
• the Nautile is battery-powered,
• the Nautile can reach depths up to 6000 meters, whereas a military submarine can only go down to a few hundred meters,
• the military submarine must be stealthy.

Three parts of the Nautile will be studied: the sphere, the propeller and a porthole.