Thucydides, History of the Peloponnesian War
Benjamin Jowett, Ed.

13. The Peloponnesians, having continued their efforts during this day and a part of the next,¹ at length desisted; on the third day they sent some of their ships to Asinè for timber with which to make engines, hoping by their help to take the part of the fort looking towards the harbour where the landing was easier, although it was built higher. [2] Meanwhile the Athenian ships arrived from Zacynthus; they had been increased in number to fifty by the arrival of some guardships from Naupactus and of four Chian vessels. [3] Their commanders saw that both the mainland and the island were full of hoplites, and that the ships were in the harbour and were not coming out: so, not knowing where to find anchorage, they sailed away for the present to the island of Protè, which is close at hand and uninhabited, and there passed the night. Next day, having made ready for action, they put off to sea, intending, if, as they hoped, the Peloponnesians were willing to come out against them, to give battle in the open; [4] if not, to sail into the harbour. The Peloponnesians did not come out, and had somehow neglected to close the mouths as they had intended. They showed no sign of moving, but were on shore, manning their ships and preparing to fight, if any one entered the harbour, which was of considerable size.