First - rate First rate was the designation used by the Royal Navy for its largest ships of the line . While the size and establishment of guns and men changed over the 250 years that the rating system held sway , from the early years of the 1700s the first rates comprised those ships mounting 80 guns or more on three gundecks . In the Nelsonic period ( around 1800 ) , a first rate carried over 800 crew and displaced in excess of . Rating . When the original rating system evolved during the first part of the 1600s , first rates were ships with a complement of at least 300 men ( it was not until after 1660 that the number of carriage - mounted guns became the deciding criterion ) . Early first rates had as few as 60 guns , but by the mid - 1660s first rates generally carried between 90 and 100 guns . By the early years of the 1700s it became accepted that 100 guns was the standard criterion for a first rate in wartime ( while 90 guns , later 98 guns , became the standard wartime ordnance for a second rate ) . ( In peacetime , all ships of the line carried a reduced complement of guns . ) Towards the close of the century , ships were built with more than 100 guns , and they too were classed as first rates . In addition to the rated number of carriage - mounted guns ( which included the heaviest calibre available mounted on their lower decks , with smaller guns on the decks above ) , first rates also carried a number of anti - personnel guns , initially swivel - mounted weapons . From the invention of the slide - mounted carronade in the later 1770s , first rates ( like other warships ) could mount a number of these on their quarterdecks and forecastles to augment their short - range firepower , but these were not included in the ship ' s rating until 1817 except where they replace carriage - mounted guns . Although very powerful , first rates of the 1600s and 1700 ' s tended to be slow and unhandy . For stability , the lowest gundeck had to be very close to the water , and in anything but calm water the gunports had to be kept closed , rendering the entire deck useless . With later ships built with more freeboard ( the height above the waterline of the sill of the lowest port ) , these problems were gradually overcome . Ships of this size were also extremely expensive to operate . As a result , the few first rates ( the Royal Navy had only five completed in 1794 ) were typically reserved as commanding admiral s ' flagship s . First rates were typically kept out of commission ( " in Ordinary " ) during peacetime and only activated ( " commissioned " ) during times of conflict . This had the added advantage of preserving them from the wear and tear that smaller ships experienced in spending long periods at sea . Spending time in ordinary could considerably extend a first rate ' s lifespan ; for instance , by the time she fought in the Battle of Trafalgar , HMS " Victory " had been in service for 40 years , although a portion of these years were spent in Ordinary . These being the most powerful ships of the navy , it was common to compare them with the navies of other nations , and frequently one sees the largest ships of those navies being referred to as first rates . Other nations had their own rating systems , notably the French Navy with its system of five formal rates or " rangs " . Ships . Because of their unique importance as prestige warships , only a small number of first rates could be built and maintained at any one time . Thus over the 250 years ( approximately ) that the rating system of the Royal Navy held sway , only a relatively small number of first rates saw service . Only one first rate has survived to the present . HMS " Victory " , Vice - Admiral Nelson ' s flagship at the Battle of Trafalgar , is preserved at HMNB Portsmouth as an active warship in commission . The hull of the 112 - gun HMS " St Lawrence " , which was built and operated entirely in fresh water during the War of 1812 , survives intact in shallow water near shore in Kingston , Ontario and is a popular diving attraction . Two other famous first rates were , which was broken up in 1841 , and , which was broken up in 1825 . Both these ships had 100 guns . Later first rates such as the " Caledonia " and its several sisters had 120 guns . Other navies , notably those of France and Spain , also had similar ships with more than 100 guns , the most heavily - armed being the Spanish " Santísima Trinidad " which , following a rebuilding in 1802 , carried 140 guns . Other usage . The term " first - rate " has passed into general usage as an adjective used to mean " exceptionally good " , although this was in no way its meaning in naval classification .