Ancient writers demonstrate that some sailing activity went on in the Mediterranean year-round.
Much was small-scale and local in boats that would seek a safe harbor every night (e.g. Demosthenes 56, 30).
More important, however, for our understanding of ancient warfare, galleys could sail all winter if required (e.g., Thucydides 2, 33 ; 2, 69 ; 4, 101ff. ; Caesar, ciu. 3, 6-8).
