Sentence:  Having passed across in sight of this place, the Santa Anna tacked and stood off, as though she were awaiting a pilot, but none appearing, <WSD>southered</WSD> her course as if about to proceed down the coast ; having, however, rounded a small island in the river's mouth, covered with lofty trees, which completely concealed their presence, they again anchored. 
Meaning of the word marked with <WSD> tags:  To move toward the south.