Note: Do not rely on this information. It is very old.
Heligoland Battleof
Heligoland, Battle of, an action fought off Heligoland on May 9th, 1864, between, on the one hand, two Austrian frigates and three Prussian gunboats under Commodore Tegethoff, and, on the other, three Danish frigates under Commodore Svensen. The allies got slightly the worst of it, and ended the battle by taking refuge in neutral waters.