Doppler current profiler observations of an inertial wave packet are presented from a region where a cold-core ring impinges on a front. In this intense current a drogue is deployed to mark one region of the fluid. As the drogue is advected by the current, the ship follows it, zigzagging across the drogue's trajectory. Along this ship track, vertical rotary velocity spectra indicate the presence of a downgoing inertial wave with a vertical wavelength which slowly changes from ~50 to ~100 m as time progresses. The wave's intrinsic frequency was measured for the first time ever. A horizontally synoptic data set is obtained at the drogue depth by correcting for frontal advection and the temporal rotation of the wave velocity. Examination of these synoptic data indicates the presence of a southgoing near-inertial wave with horizontal wavelength ~20 km. The wave is confined to a 25-km region. Supplementary ray-tracing calculations through objective maps of the ring flow field indicate that the wave is strongly influence by Doppler shifting. This is accompanied by a slow counterclockwise turning of the horizontal wave number vector, a decrease in the intrinsic frequency, and an increase in the vertical wavelength, in qualitative agreement with the data. A companion paper (Marmorino et al., this issue) details the effect of this inertial wave upon the small-scale temperature activity with horizontal length scales of 1--3 m. ¿ American Geophysical Union 1987