In the British Royal Navy, a second rate was a ship of the line which by the start of the 18th century mounted 90 to 98 guns on three gun decks; earlier 17th-century second rates had fewer guns and were originally two-deckers or had only partially armed third gun decks.
The term in no way implied that they were of inferior quality. They were essentially smaller and hence cheaper versions of the three-decker first rates. Like the first rates, they fought in the line of battle, but unlike the first rates, which were considered too valuable to risk in distant stations, the second rates often served also in major overseas stations as flagships. They had a reputation for poor handling and slow sailing. They were popular as Flagships of admirals commanding the Windward and/or leeward islands station, which was usually a Rear Admiral of the Red.
Typically displacing around 2000 tons and carrying a crew of 750, the second rates by the second half of the 18th century carried 32-pounder guns on the gun deck, with 18-pounders instead of 24-pounders on the middle deck, and 12-pounders on the upper deck (rather than 18- or 24-pounders on first rates), although there were exceptions to this. Both first and second rates carried lighter guns (and, after 1780, carronades) on their forecastles and quarterdecks.
The three-decker second rate was mainly a British type, and was not built by other European navies to any great degree. Apart from its unhandiness, in terms of sheer firepower it was matched or even over matched by many of the large 80-gun and 74-gun two-deckers used by the French and Spanish navies instead. The additional deck did, however, give the second rate an advantage in close combat, and it had the further tactical advantage of sometimes being mistaken by the enemy for a first rate, which could possibly make enemy commanders reluctant to press an attack.
The term "" has since passed into general usage as an adjective used to mean of suboptimal quality, inferior to something that is "".