Battle of Heligoland ( 1864 ) The Battle of Heligoland ( or Helgoland ) was fought on 9 May 1864 , during the Second War of Schleswig between the navy of Denmark and the allied navies of Austria and Prussia south of the then - British North Sea island of Heligoland where the Battle of Heligoland ( 1849 ) had taken place . When the Danish forces had caused the flagship of the Austrian commander , Freiherr von Tegetthoff , to burst into flames , he withdrew his squadron to neutral waters around Heligoland . It was the last significant naval battle fought by squadrons of wooden ships and also the last one involving Denmark . Although the battle ended with a tactical victory for Denmark , it had no impact on the outcome of the war . A general armistice came into effect on 12 May , and Denmark had lost the war . The battle . As the Danish squadron approached from the north , it sighted the British frigate " Aurora " at about 10 a . m . and soon afterwards five more ships to the Southwest . The two squadrons approached each other , and " Schwarzenberg " opened fire at 13 . 15 p . m . The Danes closed and returned fire when the distance had much shortened . When Tegetthoff altered course to the West in an effort to " cross the T " , Suenson turned to port . With the Prussian gunboats unable to keep pace and far behind , the Austrian and Danish squadrons passed each other at a distance of about , exchanging furious fire . Tegetthoff turned about so as to prevent the gunboats being cut off , and both flotillas then sailed on a parallel course southwest , continuing to battle each other . " Niels Juel " duelled " Schwarzenberg " , while " Jylland " and " Hejmdal " concentrated on " Radetzky " . The Prussian gunboats were too far away to play a role . At about 15 . 30 p . m . , " Schwarzenberg " caught fire and was unable to continue . Tegetthoff broke off the encounter and took his ships into the neutral waters near Heligoland . " Aurora " had observed the action and stood ready to protect the neutrality of the British Heligoland waters , so that Suenson had to abandon his pursuit at about 16 . 30 p . m . Aftermath . Suenson waited outside the British zone of , but the Austrian - Prussian squadron was able to escape during the night to Cuxhaven at the mouth of the Elbe . With the armistice set to come into effect on 12 May , Suenson was ordered back to Copenhagen , thus ending the naval blockade . In Denmark as in Austria , the outcome of the battle was regarded as a victory . The Danish squadron was enthusiastically welcomed in Copenhagen , while in Austria , Tegetthoff was awarded with his promotion to rear admiral . He subsequently led the reform of the Austrian naval establishment . The frigate " Jylland " is today located in a drydock in a maritime museum in Ebeltoft , Denmark . Order of battle . Denmark ( Captain Edouard Suenson ) Austria ( Captain Wilhelm Freiherr von Tegetthoff ) Prussia Memorials . There is a memorial commemorating fallen Austrian sailors and marines from the battle , in a park in Altona , Hamburg , Germany . In Copenhagen , at Nyboder , there is a monument conmemorating Edouard Suenson who led the Danish forces in the battle .