  Despite the dramatic progress made in neutrino oscillation studies recently,
several fundamental neutrino parameters remain either unknown or poorly
measured. We discuss in detail a method for their measurement by precision
studies of oscillation-caused neutrino energy spectrum distortions, for which a
large underwater inverse beta decay detector appears to be a perfect tool.
Results determine optimal baselines and necessary exposures in the presence of
systematic uncertainties and the unavoidable background from terrestrial
antineutrinos.
