Third-rate

This article is about Royal Navy ships of the line. For the adjective meaning that something is of inferior quality, see wikt:third-rate. For the rating of late Georgian and early Victorian buildings, see Building Act 1774.

HMS Buckingham, a third-rater, on the stocks before its 1751 launch.
A model of a third-rate ship of the line of the Navy of the Order of Saint John from the late 18th century.

In the rating system of the Royal Navy, a third rate was a ship of the line which from the 1720s mounted between 64 and 80 guns, typically built with two gun decks (thus the related term two-decker).