Ships sailing along the north coast of Java were greatly influenced by land and sea breezes. During the eastern monsoon, a vessel travelling from Batavia (west Java) to Surabaya (east Java) had to take every possible advantage of the land and sea breezes and should sail not too far from the coast. Leaving Batavia in the evening or at night, a northeasterly wind will carry the ship to a latitude of approximately 5_ 420 S, where sea breeze may be expected.