  A study of the ultra high energy neutrino detection performances of a km^3
Neutrino Telescope sitting at the three proposed sites for "ANTARES", "NEMO"
and "NESTOR" in the Mediterranean sea is here performed. The detected charged
leptons energy spectra, entangled with their arrival directions, provide an
unique tool to both determine the neutrino flux and the neutrino-nucleon cross
section.
