  The ANTARES collaboration propose to observe High Energy Cosmic Neutrinos
using a Deep Sea Cherenkov detector. The sky survey with high energy neutrinos
is complementary to the observations with photons. It is expected that this
will shed a new light on the understanding of the origin of cosmics rays, on
galactic and extra galactic sources. In this document, we will elaborate on the
potential interest of such a study for Astrophysicists and Particle Physicists.
For Oceanologists participating in the collaboration, the main goal is a long
term measurement of environmental parameters in the deep sea. We propose to
explore the possibility of a km-scale detector to be installed in a deep site
in the Mediterranean sea, for which a broad collaboration will be needed. A
variety of technical problems have to be solved. Strong constraints coming from
the deep sea environment and the lack of accessibility, require sea science
engineering expertise. For items such as detector deployment in deep water,
data transmission through optical cables, corrosion, bio-fouling of optical
modules, positioning, we have found technical support from collaborators and
partners which have experience in this field (COM, CSTN, CTME, IFREMER, France
Telecom Cables, INSU-CNRS...). We will test the sea engineering part of a
detector including test deployments close to the Toulon coast (France) where
technical support is available and where several sites at depths down to 2500 m
are easily accessible. During the same time, issues connected to the
accomplishment of a large scale detector and the selection of an optimum site
will be addressed. We propose to build and install a demonstrator (a fully
equipped 3-dimensional test array) the design of which can be extended to a
km^3 scale detector. We plan to reach this goal within the next 2 years.
