For the island of Sphacteria, stretching along in a line close in front of the harbour, at once makes it safe and narrows its entrances, leaving a passage for two ships on the side nearest Pylos and the Athenian fortifications, and for eight or nine on that next the rest of the mainland: for the rest, the island was entirely covered with wood, and without paths through not being inhabited, and about one mile and five furlongs in length.
The inlets the Lacedaemonians meant to close with a line of ships placed close together, with their prows turned towards the sea, and, meanwhile, fearing that the enemy might make use of the island to operate against them, carried over some heavy infantry thither, stationing others along the coast.

By this means the island and the continent would be alike hostile to the Athenians, as they would be unable to land on either; and the shore of Pylos itself outside the inlet towards the open sea having no harbour, and, therefore, presenting no point which they could use as a base to relieve their countrymen, they, the Lacedaemonians, without sea-fight or risk would in all probability become masters of the place, occupied as it had been on the spur of the moment, and unfurnished with provisions.

This being determined, they carried over to the island the heavy infantry, drafted by lot from all the companies.

Some others had crossed over before in relief parties, but these last who were left there were four hundred and twenty in number, with their Helot attendants, commanded by Epitadas, son of Molobrus.
Meanwhile Demosthenes, seeing the Lacedaemonians about to attack him by sea and land at once, himself was not idle.

He drew up under the fortification and enclosed in a stockade the galleys remaining to him of those which had been left him, arming the sailors taken out of them with poor shields made most of them of osier, it being impossible to procure arms in such a desert place, and even these having been obtained from a thirty-oared Messenian privateer and a boat belonging to some Messenians who happened to have come to them.