This category's sub-categories include all articles on individual ships, a loose category that overlaps considerably with boats, the distinction being a matter of local laws or traditions, or even personal opinion. Category:Boats is included as a sub-category of "Ships by type" for vessels often considered as boats.

Sub-categories listing articles on individual ships or boats by particular types or kinds are listed under Category:Ships by type.

Category:Ship types has articles on types of ships. Category:Boat types has articles on types of boats.