Vibrio mimicus, although named for having many of the same virulent factors as Vibrio cholera, is a rare cause of significant gastrointestinal illness. Like many of the Vibrio species, the strongest risk factor for V. mimicus infection is seafood consumption. After consuming crabs, a 64-year-old male presented with a three day history of voluminous, non-bloody, water diarrhea. The severity of the diarrhea caused the patient to have orthostatic hypotension and acute kidney injury, which improved with fluid resuscitation. The diarrhea resolved in 24-hours, and the patient was discharged without medications. Stool studies later returned positive for V. mimicus. Clinicians, especially those in coastal regions, should consider this rare pathogen in the setting of refractory diarrhea and a history significant for seafood consumption. With early clinical suspicion, clinicians can focus on volume repletion while limiting the use of anti-microbials.