Early in the blockade of Lilybaeum and Drepana, 50 Carthaginian quinqueremes gathered off the Aegates Islands, which lie 15–40 kilometres (9–25 mi) to the west of Sicily. Once there was a strong west wind they sailed into Lilybaeum before the Romans could react. They unloaded reinforcementseither 4,000 or 10,000 according to different ancient sourcesand a large quantity of supplies. They evaded the Romans by leaving at night, evacuating the Carthaginian cavalry. The Romans had sealed off the landward approach to Lilybaeum with earth and timber camps and walls, and now made repeated attempts to block the harbour entrance with a heavy timber boom; due to the prevailing sea conditions they were unsuccessful. The two Carthaginian garrisons were kept supplied by blockade runners. These were light and manoeuvrable quinqueremes with highly trained crews and pilots who knew the shoals and currents of the difficult waters. Chief among the blockade runners was a galley captained by Hannibal the Rhodian, who taunted the Romans with the superiority of his vessel and crew. Eventually the Romans captured Hannibal, and his well-constructed galley.