  Using the Submillimeter Array (SMA) we have imaged for the first time the
321.226 GHz, 10_{29}-9_{36} ortho-H2O maser emission. This is also the first
detection of this line in the Cepheus A high-mass star-forming region. The
22.235 GHz, 6_{16}-5_{23} water masers were also observed with the Very Large
Array 43 days following the SMA observations. Three of the nine detected
submillimeter maser spots are associated with the centimeter masers spatially
as well as kinematically, while there are 36 22 GHz maser spots without
corresponding submillimeter masers. In the HW2 source, both the 321 GHz and 22
GHz masers occur within the region of ~1'' which includes the disk-jet system,
but the position angles of the roughly linear structures traced by the masers
indicate that the 321 GHz masers are along the jet while the 22 GHz masers are
perpendicular to it. We interpret the submillimeter masers in Cepheus A to be
tracing significantly hotter regions (600~2000 K) than the centimeter masers.
