Surface discharge of negatively buoyant effluents into moving waterbodies creates a range of complex flow behavior. These complexities in the hydrodynamic phenomena develop through the interplay between a discharge's initial fluxes and the motion of the ambient current, which advects the discharge fluid downstream. In the present study, experiments were conducted for a comprehensive range of initial fluxes for negatively buoyant discharges in an ocean current through rectangular and semicircular channels. From this data, three flow regimes—the free surface jet, the shore-attached surface jet, and the plunging plume—and their range of occurrences were identified. These observations provide the basis for developing a revised flow classification diagram, which differs significantly from the positively buoyant discharge scheme as expected. A major difference is in the transition from the free surface jet regime to the shore-attached surface jet, whereas the plume-like regime has the same transition criteria. Eventually, using the developed diagrams, an initial tree-like classification framework is developed for both semicircular and rectangular discharge channels.