A chaika (, , pl. Шајкe / Šajke) was a wooden boat with a mast and sail, a type of galley, used in early modern warfare by the: * Zaporozhian Cossacks in the 16th–17th centuries in Ukraine on the Dnipro River and the Black Sea. * Serbs in the 16th-19th centuries on the Danube, known as Šajkaši, under Kingdom of Hungary, Austrian Empire and Habsburgs.