The discrimination of convective from stratiform tropical oceanic rains by conventional radar-based textural methods is problematic because of the small size and modest horizontal reflectivity gradients of the oceanic convective cells. In this work the vertical air motion measured by an aircraft gust probe is used as a discriminator which is independent of the textural methods. A threshold draft magnitude of ≈1 m s-1 separates the two rain types. Simultaneous airborne in situ observations of drop size distributions (DSD) made during the Tropical Ocean-Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) were used to compute Z, R, and other integral parameters. The data were quality controlled to minimize misclassifications. The convective and stratiform rains, observed just below the melting level but adjusted to surface air density are characterized by power law Z-R relations (Z=129R1.38 (convective) and 224R1.28 (stratiform)). However, at R<10 mm h-1, the convective population is essentially coincident with the small-drop size, small-Z portion of the stratiform population. Tokay and Short <1996> found a similar result when their algorithm did not separate the rain types unambiguously at R<10 mm h-1. The physical reasons for the wide variability of the drop size spectra and Z-R points in stratiform rain and their overlap with that of convective rain are proposed. The subtle distinctions in the microphysical properties and the Z-R relations by rain type could not be found by Yuter and Houze (YH) using the same airborne DSD data set as that in this work and a radar-based textural classification algorithm. ¿ 2000 American Geophysical Union