Svartholm when it became clear that Russians had beaten the blockade. Several other ships were lost during the withdrawal. The turuma Björn Järnsida, which had been Ehrensvärd's flagship at the start of the battle, ran aground and struck its colors after bravely fighting nearly to the last man. The frigate af Trolle, turuma Ragvald, and a gun sloop were also captured. Swedish auxiliaries and transport vessels trapped north of island of Kotka were burned to prevent their capture. Aftermath Total Swedish losses were three turuma archipelago frigates, one hemmema archipelago frigate, one light frigate, one galley, one half-galley, one schooner, nine gun sloops and thirty transport and auxiliary vessels. Roughly 1500 Swedes were killed, wounded or captured during the battle. A field hospital was formed for another 500 sick Swedes unable to evacuate. Russian losses were one galley and one gun sloop blown up. Russians recaptured all ships from Balle's squadron captured by Swedes early in the battle. Their casualties were 383 men killed, 628 injured and 22 captured. Russians gained a clear victory but failed to inflict decisive defeat on the Swedish archipelago fleet. A delayed attack by Karl Heinrich von Nassau-Siegen allowed Swedes to defeat Ivan Balle's squadron. Early defeat of Balle's squadron allowed most of the Swedish fleet to reach the safety of Svartholm fortress and regroup for later battles. Navigation of the shallow yet unobstructed narrow between Tiutine and Koiromsari by Giulio Litta's small galley force was the crucial factor in Russian success at Svensksund. Several factors contributed to the Swedish defeat. A successful Russian blockade at Porkkala prevented two archipelago frigates, roughly twenty galleys, and several gun sloops and yawls from reaching Svensksund in August 1789. Ehrensvärd's preparations for defense were hampered by King Gustav III's opposition to his plan. Ehrensvärd's decision not to blockade the narrow between Tiutine and Koiromsari due to his belief that it was too shallow to navigate was a crucial error; and delayed construction of obstacles in the straits opening towards Frederikshamn made it possible for the Russians to clear them quickly. Inadequate sounding of the Swede's selected battleground caused several Swedish ships to run aground during the battle. The Swedes might have been victorious at Svensksund in 1789 had the king allowed Ehrensvärd to withdraw to Svartholm after defeating Balle's squadron as Ehrensvärd had planned. King Gustav III was aware his fleet was running low on ammunition when he