Early on 9 May, Tegetthoff received word that the Danish squadron was cruising off Helgoland. He immediately sortied, and by 10:00 approached the Danish warships. Shortly after 10:00, lookouts aboard the Danish vessels spotted smoke from Tegetthoff's ships approaching from the south. Three hours later, the two squadrons were in visual range, and "Aurora", which had been observing the Danish squadron, took up a position to delineate the neutral waters around the island. A little after 13:30, the Austrian, Prussian, and Danish commanders all ordered their crews to clear for action. The Austro-Prussian squadron opened fire first, at 13:57, with "Schwarzenberg"s bow guns at a range of about . The two squadrons, in line ahead formation with the Prussian vessels lagging behind, closed to about and passed in opposite directions, firing broadsides at each other. A shell from "Niels Juel" struck "Schwarzenberg" and killed or wounded most of the men on one of her starboard guns.