Although the "diekplous" is considered to be one of the most effective maneuvers in naval warfare, it was only successfully used in three battles: Lade, Chios, and Side. One reason why the tactic became less useful was that enemies quickly developed defensive tactics against it. One way opponents countered the "diekplous" was by retreating their fleet into a tight circle with the hulls of their ships facing outward. This defensive maneuver was known as the hedgehog counter-formation. The tight circle prevented the Greek navy from infiltrating its opponent's squadron because if the navy used the "diekplous", the galley would be encircled by its enemy and rammed. This counter formation was used by Themistocles in the Battle of Artemisium.