Sea dog is a maritime term used to refer to sailors or other individuals who spend a lot of time on the sea. There are several synonyms for sea dog, including mariner, seafarer, sailor, seaman, and boater. These words all describe someone who works or travels on a vessel over the course of an extended period. Other synonyms for sea dog include salt, ocean-goer, old salt, and sea wolf. These words speak to the rugged, weathered nature of someone who has spent significant time on the water, often evoking images of grizzled sailors with stories to tell. Regardless of the term used, all of these synonyms connote someone with experience and familiarity with the ocean.