Despite the massive buildup, the Roman crews remained inferior in naval experience to the Carthaginians, and could not hope to match them in naval tactics, which required great maneuverability and experience. They, therefore, employed a novel weapon that transformed sea warfare to their advantage. They equipped their ships with the "corvus", possibly developed earlier by the Syracusans against the Athenians. This was a long plank with a spike for hooking onto enemy ships. Using it as a boarding bridge, marines were able to board an enemy ship, transforming sea combat into a version of land combat, where the Roman legionaries had the upper hand. However, it is believed that the "Corvus"' weight made the ships unstable, and could capsize a ship in rough seas.