But the new consul Publius Claudius considered the task of maintaining the investment of Lilybaeum too trifling:  he preferred to change once more the plan of operations, and with his numerous newly-manned vessels suddenly to surprise the Carthaginian fleet which was waiting in the neighbouring harbour of Drepana.  With the whole blockading squadron, which had taken on board volunteers from the legions, he started about midnight, and sailing in good order with his right wing by the shore, and his left in the open sea, he safely reached the harbour of Drepana at sunrise.  Here the Phoenician admiral Atarbas was in command.  Although surprised, he did not lose his presence of mind or allow himself to be shut up in the harbour, but as the Roman ships entered the harbour, which opens to the south in the form of a sickle, on the one side, he withdrew his vessels from it by the opposite side which was still free, and stationed them in line on the outside.  No other course remained to the Roman admiral but to recall as speedily as possible the foremost vessels from the harbour, and to make his arrangements for battle in like manner in front of it; but in consequence of this retrograde movement he lost the free choice of his position, and was obliged to accept battle in a line, which on the one hand was outflanked by that of the enemy to the extent of five ships —­for there was not time fully to deploy the vessels as they issued from the harbour—­and on the other hand was crowded so close on the shore that his vessels could neither retreat, nor sail behind the line so as to come to each other’s aid.  Not only was the battle lost before it began, but the Roman fleet was so completely ensnared that it fell almost wholly into the hands of the enemy.  The consul indeed escaped, for he was the first who fled; but 93 Roman vessels, more than three-fourths of the blockading fleet, with the flower of the Roman legions on board, fell into the hands of the Phoenicians.  It was the first and only great naval victory which the Carthaginians gained over the Romans.  Lilybaeum was practically relieved on the side towards the sea, for though the remains of the Roman fleet returned to their former position, they were now much too weak seriously to blockade a harbour which had never been wholly closed, and they could only protect themselves from the attack of the Carthaginian ships with the assistance of the land army.  That single imprudent act of an inexperienced and criminally thoughtless officer had thrown away all that had been with so much difficulty attained by the long and galling warfare around the fortress; and those war-vessels of the Romans which his presumption had not forfeited were shortly afterwards destroyed by the folly of his colleague.