Infections associated with marine activities, particularly work or recreation in salt water, present unique diagnostic challenges for the infectious disease practitioner. Those caused by halophilic, non-cholera Vibrio species are increasingly being recognized in clinical practice. They typically follow saltwater injuries, especially those associated with coral. Because these infections can be both severe and life-threatening, a consideration of halophilic Vibrio species in the differential diagnosis of marine-acquired infections is important. In this case report, we discuss the diagnosis and treatment of cellulitis in a patient with a Caribbean coral injury associated with Vibrio alginolyticus cellulitis.