Turuma A turuma was a type of warship built for the Swedish archipelago fleet in the late 18th and early 19th centuries . It was developed for warfare in the Archipelago Sea and along the coasts of Svealand and Finland against the Russian navy . The turuma was designed by the prolific naval architect Fredrik Henrik af Chapman for use in an area of mostly shallow waters and groups of islands and islets that extend from Stockholm all the way to the Gulf of Finland . Background . In the early 18th century , the establishment of Russian naval power in the Baltic challenged the interests of Sweden , at the time one of the major powers in the Baltic . The Swedish empire at the time included territory in Northern Germany , all of modern Finland and most of the Baltic states , a dominion held together by the Baltic sea routes . Russian Tsar Peter the Great had established a new capital and naval base in Saint Petersburg in 1703 . During the Great Northern War Sweden lost its Baltic state territories , and experienced destructive Russian raiding in Finland and along the chain of islands and archipelagos that stretched all the way from the Gulf of Finland to the capital of Stockholm . The traumatic experience led to the establishment of inshore flotillas of shallow - draft vessels . The first of these consisted mainly of smaller versions of the traditional Mediterranean warship , the galley s . Most of these more akin to galiot s and were complemented with gun prams . The disastrous war against Russia 1741 - 43 and the minor involvement in Prussia in the Seven Years ' War 1757 - 62 showed the need for further expansion and development of the inshore flotillas with more specialized vessels . Traditional galleys were effective as troop transports for amphibious operations , but were severely under - gunned , especially in relation to their large crews ; a galley with a 250 - man crew , most of whom were rowers , would typically be armed with only one 24 - pounder cannon and two 6 - pounders , all in the bow . However , they were undecked and lacked adequate shelter for the rower - soldiers , great numbers of which succumbed to illness in the war of 1741 - 43 . The Swedish military invested considerable resources into the establishment of the " archipelago fleet " ( " skärgårdsflottan " ) , a separate branch of the armed forced that organizationally belonged to the army . In 1756 , it was even officially designated " Arméns flotta " , " Navy of the Army " , though it was in many ways a highly independent organization that attracted a social and cultural elite and enjoyed the protection of Gustav III after his 1772 coup that empowered him as an absolute monarch . Several new ships were designed by the naval architect Fredrik Henrik af Chapman to bolster the hitting - power of the new Swedish arm , to provide it with better naval defense and greater fire support capabilities during amphibious operations . The result was four new vessels that combined the maneuverability of oar - powered galleys with the superior rigs and decent living conditions of sailing ships : the udema , pojama , turuma and hemmema , named after the Finnish regions of Uusimaa ( genitive form : " Uudenmaan " ) , Pohjanmaa , Turunmaa and Hämeenmaa ( Tavastia ) . All four have been referred to as " skärgårdsfregatter " , " archipelago frigates " , in Swedish and English historical literature , though the smaller udema and pojama have also been described as " archipelago corvettes " . The name " turuma " has been carried on ( in its more modern variant ) as a traditional vessel name in the Finnish navy , with several ships named after the type . Design . The first turuma was completed in 1761 . Along with the hemmema , it was the type of " archipelago frigate " that closest fit the description , showing considerable similarities with small ocean - going frigates . It had a low hull with no forecastle , only a low quarterdeck and no poop deck . It had three masts that were initially rigged with lateen sails , like a galley , which was later replaced with a conventional square frigate rig , but with combined top and topgallant masts . This improved its performance under sail and made it the best sailer in the archipelago fleet , though it was still slower than ordinary sailing vessels . The first turuma , " Norden " , was c . 35 m ( 116 ft ) long and 8 m ( 26 . 5 ft ) wide with a draft of 3 . 3 m ( 11 ft ) . By the third ship , the " Lodbrok " ( 1771 ) , the hull had been expanded to 38 . 5 m ( 126 ft ) by 9 . 5 m ( 31 ft ) and remained roughly the same . The armament was considerably heavier than that of the galleys , or the smaller udema s and pojoma s . It had one full gundeck of 22 ( 24 in the ships built before 1790 ) 12 - pounders in a regular broadside arrangement , firing through gunport s . On the forecastle deck facing straight forward were two 18 - pounders . For close - range action it carried another up to 24 3 - pound swivel gun s along the railings . In addition , there was also two 12 - pound stern chasers . For additional maneuverability , the turuma carried 19 pairs ( 16 in the first two ships ) of oars with four men per oar . Oarsmen rowed sitting on the weather deck , above the gun deck , with the oarpoarts attached to a rectangular outrigger that was designed to improve the leverage . Despite this , turumas performed poorly under oars and were very difficult to move in any kind of contrary wind . In calm weather the average speed with oars was reported as low as half a knot . The turuma ' s design was very similar to one of the other types of archipelago frigates , the hemmema . The primary difference was that hemmemas were rowed from the gundeck , providing the oarsmen with better leverage by placing them closer to the waterline . The later hemmema s were also considerably larger , more heavily armed and of a more robust construction . Naval historian Jan Glete has gone as describing them as variations on the same type , especially when considering the pre - war designs . The crew varied between 220 and 266 , depending on the model . Between 128 and 152 of these were required to man all the oars . The concept of hybrid frigates with oar propulsion capabilities was not new . Small " galleass es " had been built for the English navy as early as the mid - 16th century , and the Royal Navy had equipped the equivalent of sixth rate s with oar ports on or below the gundeck as early as the 1660s . " Shebecks " , Baltic variations on the Mediterranean xebec s , had been introduced in the Russian navy for inshore duties during the 18th century . Both of these have been suggested as possible inspirations for af Chapman ' s new designs . Though not identical to the Mediterranean - inspired vessel , the Russian navy considered turumas similar enough in function to their own " shebecks " to use this terminology when referring to Swedish prizes ( captured ships ) . Special - purpose ships . In 1777 , Chapman designed a special version of a turuma called the " Amphion " , which was intended as a royal yacht . It was 33 . 5 m ( 110 ft ) long and 6 . 8 m ( 22 . 25 ft ) wide and was schooner - rigged with only two masts ( later changed to a brigantine rig ) . Chapman intended for the craft to carry a broadside armament similar to that of the regular turumas , but this was rejected by Gustav who ordered the craft to be built with an armament consisting of only light swivel guns . The " Amphion " was decorated in the more stringent version of Rococo that in Sweden is defined as " Gustavian " , and was fitted with a great cabin with a skylight that was well - suited for royal audiences and conferences . The " Amphion " served as the king ' s personal command ship in the war of 1788 - 90 , but was such a poor sailer that the king and his retinue abandoned it during the dramatic escape from Vyborg Bay in 1790 . Service . Seven turumas were built for the Swedish navy before the Russian war of 1788 - 90 , and another six were complete during the war , with one more built after 1790 . Altogether fourteen turumas were completed , making it the most common of the four archipelago frigate types . At the outbreak of war in 1788 , they formed the core of the archipelago flotilla in Finland . They were used to support amphibious operations and to conduct raids on the Russian archipelago fleet , while at the same time acting as a sea - borne flank support for the Swedish army on the Finnish mainland . Turumas fought in both the first and second battles of Svensksund . In the first in August 1789 , six turumas made up the bulk of the firepower of the larger Swedish vessels , while at the second in July 1790 , it was reduced to just one ship . Like the other specialized archipelago vessels , the turuma had only limited advantages . While it had superior firepower , its sailing qualities were only average and they were slow under oars . It had the potential to be an effective weapon against galleys , matching their forward firepower and severely outgunning them with its broadside armament . Inside an enemy galley formation , it could wreak considerable havoc , but such a maneuver was never achieved in an actual battle , leaving that tactical role untested . Like the hemmema , the turuma was effective in defensive formations , but lacked the mobility that was often needed in offensive archipelago warfare . In 1790 , after the war ended , two were converted into hospital ship s . The second battle of Svensksund had clearly showed that the smaller and nimble gunboats and gunsloops were far more efficient in coastal warfare and had all but displaced " archipelago frigates " in the inshore squadrons by the Finnish War of 1808 - 9 . Ships . Seventeen turumas were built , all for the Swedish archipelago fleet , including the specially designed royal yacht " Amphion " . The individual ships are listed below with year of launching in parenthesis .