  We report on the results of a Monte Carlo simulation study of a km^3 scale
deep underwater Cherenkov detector aimed at detecting neutrinos of
astrophysical origin. This analysis has been undertaken as part of the NEMO R&D
project to develop such an experiment close to the Southern Italian coasts. We
have studied the reconstruction capabilities of various arrays of phototubes in
order to determine the detector geometries which optimize performance and cost.
We have also investigated the possibility of designing a detector with
characteristics suited to an experiment on atmospheric neutrino oscillations.
