A trading vessel or trading ship was a type of spacecraft used for trade. Carter Winston had such a vessel. In, after a Vendorian posing as Winston had been rescued by USS Enterprise, Spock noted that extreme long-range sensors detected something in the Romulan Neutral Zone. He speculated that it might be another trading vessel like Winston's, but couldn't be certain due to their distance from the object. (TAS: "The Survivor")