  We report here the correlation between the water content and
superconductivity in Na0.3CoO2*yH2O under the influences of elevated
temperature and cold compression. The x-ray diffraction of the sample annealed
at elevated temperatures indicates that intergrowths exist in the compound at
equilibrium when 0.6 < y < 1.4. Its low-temperature diamagnetization varies
linearly with y, but is insensitive to the intergrowth, indicative of quasi-2D
superconductivity. The Tc-onset, especially, shifts only slightly with y. Our
data from cold compressed samples, on the other hand, show that the water-loss
non-proportionally suppresses the diamagnetization, which is suggestive of weak
links.
