Coastal defence ship Coastal defence ships ( sometimes called coastal battleships or coast defence ships ) were warship s built for the purpose of coastal defence , mostly during the period from 1860 to 1920 . They were small , often cruiser - sized warships that sacrificed speed and range for armour and armament . They were usually attractive to nations that either could not afford full - sized battleship s or that could be satisfied by specially designed shallow - draft vessels capable of littoral operations close to their own shores . The Nordic countries and Thailand found them particularly appropriate for their island - dotted coastal waters . Some vessels had limited blue - water capabilities ; others operated in rivers . The coastal defence ships differed from earlier monitors by having a higher freeboard and usually possessing both higher speed and a secondary armament ; some examples also mounted casemate d guns ( monitors ' guns were almost always in turrets ) . They varied in size from around 1 , 500 tons to 8 , 000 tons . Navies with coastal defence ships serving as their main capital ship s included those of Belgium , Ecuador , Finland , Greece , the Netherlands , Norway , Portugal , Sweden , Thailand , and the British colonies of India and Victoria . Some nations which at one time or another built , bought , or otherwise acquired their own front - line capital ships , such as Argentina , Austria - Hungary , Brazil , China , Germany , Russia , and Spain , also deployed this type of warship , with Russia using three at the Battle of Tsushima in 1905 . Apart from specially built coastal defence ships , some navies used obsolescent pre - dreadnought battleships in this role . The Royal Navy deployed four s as guardships in the Humber at the start of the First World War . Similarly , the U . S . Navy redesignated the and classes as " Coast Defense Battleships " in 1919 . Such ships tended to be near the end of their service lives and while generally considered to no longer be fit for front - line service , they were still powerful enough for defensive duties in reserve situations . Categorization . This type of vessel has always been categorized differently by different countries , due to treaties , differences in judgments related to design or intended roles , and also national pride . In the United Kingdom the Scandinavian ships were known as " coast defence ships " . The Germans called these ships " Küstenpanzerschiff " ( " coastal armoured ship " ) . The Danes referred to their ships as " Kystforsvarsskib " ( " coast defence ship " ) and " Panserskib " ( " armoured ship " ) . In Norway they were referred to as " Panserskip " ( " armoured ship " ) . The Dutch called their ships " Kruiser " ( " cruiser " ) , " Pantserschip " ( " armoured ship " ) or " Slagschip " ( " battleship " ) . The Swedish term for these ships was " Pansarskepp " ( " armored ship " ) . As an example of the profusion of terms and classifications which often contradicted each other , the 1938 edition of " Jane ' s Fighting Ships " lists the Swedish " Pansarskepps " of the " Sverige " class as battleships . The Swedish " Pansarskepp " . The Swedish " Pansarskepp " were an outgrowth of the earlier Swedish adoption of the monitor and were used for similar duties . Technical details . The " Pansarskepp " , with the notable exception of the , were relatively small vessels with limited speed , shallow draft , and very heavy guns relative to the displacement . They were designed for close in - shore work in the littoral zone of Scandinavia , and other countries with shallow coastal waters . The aim was to outgun any ocean - going warship of the same draft by a significant margin , making it a very dangerous opponent for a cruiser , and deadly to anything smaller . The limitations in speed and seaworthiness were a trade - off for the heavy armament carried . Vessels similar to the Swedish " Pansarskepp " were also built and operated by Denmark , Norway , and Finland , all of which had similar naval requirements . Effectiveness . The " Sverige " - class ships differed in several ways from the classical coastal defence ship , having heavier armament as well as better speed and armor ( while still being small enough to operate and hide in the archipelagos and shallow waters off Sweden ) . The main difference was to be noted in their tactical doctrine and operations . Unlike other coastal defence ships the " Sverige " - class formed the core of a traditional open - sea battle group ( Kustflottan ) , operating with cruisers , destroyer s , torpedo boat s , and air reconnaissance in conformance with traditional battleship tactics of the time . This “ mini - battle group ” had no intention of challenging the superpowers in blue - water battles , but rather were to operate as a defensive shield to aggression challenging Swedish interests and territory . Based on the doctrine that one needs a battle group to challenge other battle groups , this force intended to form a problematic obstacle in the confined and shallow Baltic and Kattegat theatre , where traditional large warships would be limited to very predictable moving patterns exposing them to submarines , fast torpedo craft , and minefields . It has been suggested that the " Sverige " - class ships were one reason why Germany did not invade Sweden during World War II . Such speculation appeared in " Warship Magazine Annual 1992 " in the article ' The Sverige Class Coastal Defence Ships , ' by Daniel G . Harris . This could be said to have been partly confirmed in the post war publication of German tactical orders , and of scenarios regarding attacking Sweden . The problems of maintaining an army in Sweden without sea superiority were emphasized , and the lack of available suitable units to face the Swedish navy was pointed out ( “ Stations for battle ” , Insulander / Olsson , 2001 ) . Summarizing the question of effectiveness for the " Sverige " - class , it is likely that despite a good armament they would have been too small , slow , and cramped ( from both a habitability and essential ship ' s stores standpoint ) , along with having insufficient range , to perform adequately against any traditional battlecruiser or battleship in a blue - water scenario ; however , if correctly used in their home waters and in a defensive situation , they would probably have presented a major challenge for any aggressor . The Dutch " Pantserschepen " . The Dutch used their armoured ships mainly to defend their interests overseas , in particular their colonial possessions in the West Indies ( the islands of the Netherlands Antilles ) and the East Indies ( primarily , modern Indonesia ) . For this reason the ships had to be capable of long - range cruising , providing artillery support during amphibious operations , and carrying the troops and equipment needed in these operations . At the same time , the ships had to be armed and armoured well enough to face contemporary armoured cruisers of the Imperial Japanese Navy ( the Netherlands ' most likely enemy in the Pacific ) , and as such they were expected to act as mini - battleships rather than strictly as coastal defence vessels . The last Dutch " pantserschip " , HNLMS " De Zeven Provinciën " , was built in 1909 as a stop - gap measure while the Dutch Admiralty and government contemplated an ambitious fleet plan comprising a number of dreadnought battleships . This ambition was never realized due to the outbreak of the First World War . The Second World War put an end to a similar project to obtain fast capital ships in the late 1930s with German assistance . Prior to the Second World War , the Dutch had relegated all the surviving " pantserschips " to secondary duties . The Axis powers , who seized some of the ships following the conquest of the Netherlands , converted several to serve as floating anti - aircraft batteries and subsequently utilized some as block ship s .