Phormio chose to attack this formation by using a risky and unorthodox tactic. He led his ships, in line, in a tightening circle around the Peloponnesians, darting inwards at times to drive the defending ships closer to each other. This tactic left the Athenians highly vulnerable to a swift attack, as any of the defending ships would only have to move a short distance straight ahead to ram a circling Athenian ship in the side. No such attack materialized, however, and the Peloponnesians were driven closer and closer together.