Similarities in their basic features, including spatial variations of frontal structure along the current, suggest that Gulf Stream meanders are dynamically analogous to atmospheric jet stream waves, with descending motions upstream and ascending motions downstream from a wave trough. In a symmetrical wave with uniform speed along the current it is shown that confluence, together with the distribution of vertical motions, accounts for the greater baroclinity in the frontal zone at troughs than at crests, a necessary feature of such a wave. Gross features of the three-dimensional motions are discussed for an eddy in the process of cutting off to form a Gulf Stream ring. Prior to its detachment from the slope water mass, deduced sinking motions exceed, by 2 orders of magnitude, the vertical motions in ring eddies that have become isolated. The large downward volume flux during the formative stage is associated with the asymmetrical structure (more water pouring into a cold tongue on its west side than leaves it on its east side) and with the vertical distribution of volume transport (greater inflow than can be accommodated by horizontal expansion in the upper layers). The inflation time for a Gulf Stream ring is about a month, much shorter than the decay time.