Naval heraldry is a form of identification used by naval vessels from the end of the 19th century onwards, after distinguishing features such as figureheads and gilding were discouraged or banned by several navies.
Naval heraldry commonly takes the form of a badge, seal, crest, or coat of arms designed specifically for a ship (or a series of ships bearing the same name), which in Commonwealth navies takes the form of a large plaque, referred to as the ship's badge, mounted on the superstructure of the ship, and in the United States Navy is known as the ship's seal or ship's crest, and is primarily found on crew uniform patches. An item of naval heraldry is seen as the identifying logo of the vessel, and is commonly reproduced on hats, stationery, trophies, souvenirs, and gifts related to the ship. In many navies, the ship's badge is also displayed on the tampions - the covers for the gun muzzles.
The naval heraldric tradition follows the heraldic traditions of the country, with some distinctive variations.
Note: Although ships are commonly referred to in this article, identical or similar forms of heraldry are used for bases and facilities, organisational divisions, and land-based naval units.
The naval heraldry used by the Portuguese Navy is regulated by an ordinance of February 18, 2010, which replaced the previous ordinance of 1972.
The coats of arms consist of a round tip shield (Portuguese shield), topped by a naval crown and under which is placed a scroll with the motto or the name of the body or unit. A scroll with the war cry of the unit can be placed above the naval crown. The coat of arms may also include tenants or supporters, trophies and decorations. A coat of arms can also be used as a badge, in which case an entirely round shield is used, surrounded by a branch of laurel on the right and by a branch of oak on the left.
The following bodies and units are entitled to the use of coat of arms: