The work assigned to the _Philadelphia_ and _Vixen_ was rigorous, for the coast--fretted with shoals, reefs, and unknown currents, and harassed by sudden squalls, strong gales, and bad holding grounds--demanded unceasing watchfulness, and rendered very difficult the securing of proper food and ship's stores from the distance of the supplying base. Bad as this was in the beginning, it became worse when in October the _Vixen_ sailed eastward in search of a Tripolitan cruiser which was said to have slipped past the line at night, for then the whole duty, mainly inshore chasing, fell to the deep-draught frigate. It was while thus employed that she came to misfortune, as Cooper writes, in his History of the United States Navy: "Towards the last of October the wind, which had been strong from the westward for some time previously, drove the _Philadelphia_ a considerable distance to the eastward of the town, and on Monday, October the 31st, as she was running down to her station again with a fair breeze, about nine in the morning a vessel was seen inshore and to windward, standing for Tripoli. Sail was made to cut her off. Believing himself to be within long gun-shot a little before eleven, and seeing no other chance of overtaking the stranger in the short distance that remained, Captain Bainbridge opened fire in the hope of cutting something away. For near an hour longer the chase and the fire were continued; the lead, which was kept constantly going, giving from seven to ten fathoms, and the ship hauling up and keeping away as the water shoaled or deepened. At half-past eleven, Tripoli then being in plain sight, distant a little more than a league, (satisfied that he could neither overtake the chase nor force her ashore,) Captain Bainbridge ordered the helm a-port to haul directly off the land into deep water. The next cast of the lead, when this order was executed, gave but eight fathoms, and this was immediately followed by casts that gave seven and six and a half. At this moment the wind was nearly abeam, and the ship had eight knots way upon her. When the cry of 'half-six' was heard, the helm was put hard down and the yards were ordered to be braced sharp up. While the ship was coming up fast to the wind, and before she had lost her way, she struck a reef forwards, and shot on it until she lifted between five and six feet."