History of the Peloponnesian War

Meanwhile, as they expected the Athenian ships to arrive from Zacynthus, they intended, if they failed to take the place before, to block up the entrance of the harbour to prevent their being able to anchor inside it.

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.