  An underwater acoustic sensor array spanning ~1500 km^3 is used to search for
cosmic-ray neutrinos of ultra-high energies (UHE, E > 10^18 eV). Approximately
328 million triggers accumulated over an integrated 130 days of data taking are
analysed. The sensitivity of the experiment is determined from a Monte Carlo
simulation of the array using recorded noise conditions and expected waveforms.
Two events are found to have properties compatible with showers in the energy
range 10^24 to 5x10^24 eV and 10^22 to 5x10^22 eV. Since the understanding of
impulsive backgrounds is limited, a flux upper limit is set providing the most
sensitive limit on UHE neutrinos using the acoustic technique.
