The war in Sicily reached a stalemate, as the Carthaginians focused on defending their well-fortified towns and cities; these were mostly on the coast and so could be supplied and reinforced without the Romans being able to use their superior army to interdict. The focus of the war shifted to the sea, where the Romans had little experience; on the few occasions they had previously felt the need for a naval presence they had usually relied on small squadrons provided by their Latin or Greek allies.

According to Polybius, the Romans seized a shipwrecked Carthaginian quinquereme, and used it as a blueprint for their own ships. The new fleets were commanded by the annually elected Roman magistrates, but naval expertise was provided by the lower officers, who continued to be provided by the socii, mostly Greeks. This practice was continued until well into the Empire, something also attested by the direct adoption of numerous Greek naval terms. As novice shipwrights, the Romans built copies that were heavier than the Carthaginian vessels, and so slower and less manoeuvrable.