Corvette A corvette ( sometimes corvet ) is a small , maneuverable , lightly armed warship , originally smaller than a frigate ( 2 , 000 + tons ) and larger than a coastal patrol craft or fast attack craft ( 500 or fewer tons ) , although many recent designs resemble frigates in size and role . During the Age of Sail , corvettes were smaller than frigates and larger than sloops - of - war , usually with a single gun deck . Although almost all modern navies use ships smaller than frigates for coastal duty , not all of them use the term " corvette " ( via Middle French , from a Dutch word " corf " , a type of boat ) or equivalent . The rank " corvette captain " , equivalent in many navies to " lieutenant commander " , derives from the name of this type of ship . Sailing vessels . During the Age of Sail , corvettes were one of many types of smaller warships . They were very closely related to sloops - of - war . The role of the corvette consisted mostly of coastal patrol , fighting minor wars , supporting large fleets , or participating in show - the - flag missions . The English Navy began using small ships in the 1650s , but described them as sloops rather than corvettes . The first reference to a corvette was with the French Navy in the 1670s , which may be where the term originated . The French Navy ' s corvettes grew over the decades and by the 1780s they were ships of 20 guns or so , approximately equivalent to the British Navy ' s post ship s . The British Navy did not adopt the term until the 1830s , long after the Napoleonic Wars , to describe a small Sixth rate vessel somewhat larger than a sloop . Most corvettes and sloops of the 17th century were around in length and measured 40 to 70 tons burthen . They carried four to eight smaller guns on a single deck . Over time , vessels of increasing size and capability were called corvettes ; by 1800 , they reached lengths of over and measured from 400 to 600 tons burthen . Steam ships . Ships during the steam era became much faster and more manoeuvrable than their sail ancestors . Corvettes during this era were typically used alongside gunboats during colonial missions . Battleship s and other large vessels were unnecessary when fighting the indigenous people of the Far East and Africa . World War II . The modern corvette appeared during World War II as an easily built patrol and convoy escort vessel . The British naval designer William Reed drew up a small ship based on the single - shaft Smiths Dock Company whale catcher " Southern Pride " , whose simple design and mercantile construction standards lent itself to rapid production in large numbers in small yards unused to naval work . First Lord of the Admiralty Winston Churchill , later Prime Minister , had a hand in reviving the name " corvette " . During the arms buildup leading to World War II , the term " corvette " was almost attached to the Tribal - class destroyer . The Tribals were so much larger than and sufficiently different from other British destroyers that some consideration was given to resurrecting the classification of " corvette " and applying it to them . This idea was dropped , and the term applied to small , mass - produced antisubmarine escorts such as the of World War II . The first modern corvettes were the Flower class ( Royal Navy corvettes were named after flowers , and ships in Royal Canadian Navy service took the name of smaller Canadian cities and towns ) . Their chief duty was to protect convoys throughout the Battle of the Atlantic and on the routes from the UK to Murmansk carrying supplies to the Soviet Union . The Flower - class corvette was originally designed for offshore patrol work , and was not ideal as an antisubmarine escort ; they were really too short for open ocean work , too lightly armed for antiaircraft defence , and little faster than the merchantmen they escorted , a particular problem given the faster German U - boat designs then emerging . They were very seaworthy and manoeuvrable , but living conditions for ocean voyages were appalling . Because of this , the corvette was superseded in the Royal Navy as the escort ship of choice by the frigate , which was larger , faster , better armed , and had two shafts . However , many small yards could not produce vessels of frigate size , so an improved corvette design , the Castle class , was introduced later in the war , with some remaining in service until the mid - 1950s . The Royal Australian Navy built 60 " Bathurst " - class corvette s , including 20 for the Royal Navy crewed by Australians , and four for the Indian Navy . These were officially described as Australian mine sweepers , or as minesweeping sloops by the Royal Navy , and were named after Australian towns . The Bird - class minesweepers or trawlers were referred to as corvettes in the Royal New Zealand Navy , and two , " Kiwi " and " Moa " , rammed and sank a much larger Japanese submarine , the " I - 1 " , in 1943 in the Solomons . Modern corvettes . Modern navies began a trend in the late 20th and early 21st centuries towards smaller , more manoeuvrable surface capability . Corvettes have a displacement between and measure in length . They are usually armed with medium - and small - caliber guns , surface - to - surface missiles , surface - to - air missiles , and antisubmarine weapons . Many can accommodate a small or medium antisubmarine warfare helicopter . Most countries with coastlines can build corvette - sized ships , either as part of their commercial shipbuilding activities or in purpose - built yards , but the sensors , weapons , and other systems required for a surface combatant are more specialized and are around 60 % of the total cost . These components are purchased on the international market . Current corvette classes . Many countries today operate corvettes ; some include Argentina , Bangladesh , Brazil , Bulgaria , China , Denmark , Germany , Egypt , India , Indonesia , Iran , Israel , Italy , Pakistan , the Philippines , Poland , Portugal , Romania , Russia , South Korea , Sweden , and Turkey . Countries that border smaller seas , such as the Baltic Sea or the Persian Gulf , are more likely to build the smaller and more manoeuvrable corvettes , with Russia operating the most corvettes in the world . The first operational warship based on stealth technology was the Royal Norwegian Navy ' s " Skjold " class . The Swedish Navy introduced the similarly stealthy . The United States is developing littoral combat ship s , which will be very similar to a corvette , but their larger hulls permit space for mission modules , allowing them to undertake tasks formerly assigned to specialist classes such as minesweepers or the antisubmarine " Oliver Hazard Perry " - class frigate . The Israeli navy operates three Saar 5 - class corvettes . Built in the U . S to an Israeli design , they carry 1 Helicopter and are well - armed with offensive and defensive weapons systems , including the Barak 1 SAM , and advanced electronic sensors and countermeasures . They weigh over 1200 tons at full load . The new German navy " Braunschweig " class is designed to supplement Germany ' s fast attack craft and also incorporates stealth technology and land attack capabilities . Turkey began to build MİLGEM - class corvettes in 2005 . The MİLGEM class is designed for antisubmarine warfare and littoral patrol duty . The lead ship , TCG " Heybeliada " , entered navy service in 2011 . The design concept and mission profile of the MİLGEM class is similar to the " Freedom " class of littoral combat ships of the United States . The Greek Navy has categorised the class as fast attack missile craft . A similar vessel is the " Kilic " - class fast attack missile craft of the Turkish Navy , which is classified as a corvette by Lürssen Werft , the German ship designer .