Characteristics of dispersal and establishment for water-borne mangrove propagules, including period and pattern of floating, period of obligate dispersal, time to root firmly, longevity and vigor, are estimated for 6 spp. in Panama (Laguncularia racemosa, Avicennia germinans, A. bicolor, Rhizophora mangle, R. harrisonii and Pelliciera rhizophorae). Dispersal properties correlate with the spatial distribution of adults within the swamp. Genera whose adults are found on higher ground, on the landward edge of the intertidal zone, have small propagules that require a period of freedom from tidal inundation of approximately 5 days to establish firmly in the substrate. Genera whose adults are found on the seaward edge of the swamp, in deeper water, have large, heavy propagules.