It is not known exactly how this was done, but there are literary and visual references to the use of gestures and pipe playing to convey orders to rowers. In the sea trials of the reconstruction "Olympias", it was evident that this was a difficult problem to solve, given the amount of noise that a full rowing crew generated. In Aristophanes' play "The Frogs" two different rowing chants can be found: ""ryppapai"" and ""o opop"", both corresponding quite well to the sound and motion of the oar going through its full cycle. A varying number of marines ("epibatai"), usually 10–20, were carried aboard for boarding actions. At the Battle of Salamis, each Athenian ship was recorded to have 14 hoplites and 4 archers (usually Scythian mercenaries) on board, but Herodotus narrates that the Chiots had 40 hoplites on board at Lade and that the Persian ships carried a similar number. This reflects the different practices between the Athenians and other, less professional navies. Whereas the Athenians relied on speed and maneuverability, where their highly trained crews had the advantage, other states favored boarding, in a situation that closely mirrored the one that developed during the First Punic War. Grappling hooks would be used both as a weapon and for towing damaged ships (ally or enemy) back to shore. When the triremes were alongside each other, marines would either spear the enemy or hop across and cut the enemy down with their swords. As the presence of too many heavily armed hoplites on deck tended to destabilize the ship, the "epibatai" were normally seated, only rising to carry out any boarding action. The hoplites belonged to the middle social classes, so that they came immediately next to the trierarch in status aboard the ship. In the ancient world, naval combat relied on two methods: boarding and ramming. Artillery in the form of ballistas and catapults was widespread, especially in later centuries, but its inherent technical limitations meant that it could not play a decisive role in combat. The method for boarding was to brush alongside the enemy ship, with oars drawn in, in order to break the enemy's oars and render the ship immobile, to be finished off as convenient. Rams ("embolon") were fitted to the prows of warships, and were used to rupture the hull of the enemy ship. The preferred method of attack was to come in from astern, with the aim not of creating a single hole, but of rupturing as big a length of the enemy vessel as possible.