At the sea floor the spring vent appears to be independent of the large subsurface subsidence feature. Although their relationship at depth is not resolvable from the seismic profiles, their formation is probably a manifestation of major dissolution (mega-void) within the underlying limestone. The vent incises the most recent marine sequence, which suggests that the vent is recent. The north (left) flank of the sink is higher in elevation than the south flank (B-B’). Sediment removal from the vent may be accumulating on the prevailing down-current side of the vent. Another possibility is that the vent may occupy a fault line, with the southern flank being a down dropped block. Popenoe and others (1984) mapped numerous downward flexures and fractures traces along the northeast coast of Florida. The reflections within the Hawthorn Group show some minor displacement. There is some definite discontinuity in the reflections below the sink (B-B’) which could represent the breach within the Hawthorn and the migration pathway for the freshwater discharge. At depth in the seismic profiles the signal does appear to be slightly more chaotic than the neighboring acoustic return (outlined with yellow dashed line). This effect could be from noise in the signal caused by the sink itself, or it could be a zone of recrystallization or more advanced karst development within the Ocala Limestone. Removal of limestone by dissolution may have created a cavity and caused subsequent roof collapse and fill of the void. Increased dissolution within the Ocala Limestone would be the cause and effect of the fluid-migration pathway related to the spring vent and freshwater discharge at the sea floor.