skills in this area. Indeed, the technology of building such instruments and training
pilots and engineers has taken considerable time, so perhaps we would be wise not
to allow this heritage of the twentieth century to disappear.
Diving in a Manned Submersible
Most people who have dived with submersibles at great depths have the sensation
of succeeding in a significant accomplishment. We travel into the unknown to look
at another aspect of our Earth, which has been hidden by the sea. The sun’s light
propagates down to only about 100–150 m in the water, after which there is only
darkness for human eyes. The artificial lights used on the submersibles consist of
several projectors, which can create about 2000 W. The light projectors are located
on top of the portholes and on the mechanical arms used for sampling (See
description of Nautile). In order to obtain a fairly good color picture, the object to
be recorded should be located less than 3–4 m from the camera.
Outside a submersible, light projectors allow limited visibility, less than
10–15 m distance, but to economize energy, they are not turned on all the time, so
sometimes we navigate in the dark. Also, visibility for human eyes does exceed
45–50 m and an object will only become recognizable at \15 m depending on the
clarity of the water column.
A submersible has to be able to move freely. Because of its weight, it sinks like
a stone, descending in the water at a speed of about 30 m/min. Submersibles are
able to adjust their rate of descent by releasing weights. Also, when the submersibles have almost landed on the ocean floor, they will release weights to
obtain neutral buoyancy, so they don’t merely sit on the ocean floor but are a few
meters just above the bottom. Generally, iron pellets are stored in appropriate
reservoirs and they can be released as needed. In order to move along the sea floor,
it is important to be in a state of neutral buoyancy. The weight release mechanism
is electromagnetically and mechanically controlled from the interior of the sphere
(Fig. 3.6).
Although, I must have participated in more than 50 dives during my career,
each dive remains a unique and exciting experience. In order to retain information
from each dive, television videos and a tape recorder (which saves all the comments made inside the submersible) are also part of the data recovered during
every dive.
A Normal Diving Day
Even if all the dive objectives have been carefully prepared prior to the expedition,
the actual moment of diving remains incredibly intense and exhilarating. Scientific
and technical meetings are programmed each evening before every dive. The
Unmanned Submersibles and Robots
69
pilots and engineers has taken considerable time, so perhaps we would be wise not
to allow this heritage of the twentieth century to disappear.
Diving in a Manned Submersible
Most people who have dived with submersibles at great depths have the sensation
of succeeding in a significant accomplishment. We travel into the unknown to look
at another aspect of our Earth, which has been hidden by the sea. The sun’s light
propagates down to only about 100–150 m in the water, after which there is only
darkness for human eyes. The artificial lights used on the submersibles consist of
several projectors, which can create about 2000 W. The light projectors are located
on top of the portholes and on the mechanical arms used for sampling (See
description of Nautile). In order to obtain a fairly good color picture, the object to
be recorded should be located less than 3–4 m from the camera.
Outside a submersible, light projectors allow limited visibility, less than
10–15 m distance, but to economize energy, they are not turned on all the time, so
sometimes we navigate in the dark. Also, visibility for human eyes does exceed
45–50 m and an object will only become recognizable at \15 m depending on the
clarity of the water column.
A submersible has to be able to move freely. Because of its weight, it sinks like
a stone, descending in the water at a speed of about 30 m/min. Submersibles are
able to adjust their rate of descent by releasing weights. Also, when the submersibles have almost landed on the ocean floor, they will release weights to
obtain neutral buoyancy, so they don’t merely sit on the ocean floor but are a few
meters just above the bottom. Generally, iron pellets are stored in appropriate
reservoirs and they can be released as needed. In order to move along the sea floor,
it is important to be in a state of neutral buoyancy. The weight release mechanism
is electromagnetically and mechanically controlled from the interior of the sphere
(Fig. 3.6).
Although, I must have participated in more than 50 dives during my career,
each dive remains a unique and exciting experience. In order to retain information
from each dive, television videos and a tape recorder (which saves all the comments made inside the submersible) are also part of the data recovered during
every dive.
A Normal Diving Day
Even if all the dive objectives have been carefully prepared prior to the expedition,
the actual moment of diving remains incredibly intense and exhilarating. Scientific
and technical meetings are programmed each evening before every dive. The
Unmanned Submersibles and Robots
69