It is estimated that there are over 200 shipwrecks although only 71 are named. The first recorded wreck was in early March 1656. Two English men o'war, the "Primrose" and "Mayflower", were searching for two Spanish frigates which had been patrolling the area and had captured a Bristol bound vessel. The sixth rate, 22 gun man o'war, "Primrose" lost her main topmast near the Longships, off Land’s End and drifted onto the Seven Stones. She managed to free herself and later sank in taking sixteen men, two women and a child with her. At the investigation into the loss, Trinity House, on behalf of the Admiralty, stated that they could not find any chart that showed the reef. The Admiralty found that there was no neglect either by the Officers or company, the place of wreck being a rock not visible nor described in any chart they could find. The largest loss of life was on 27 February 1748 with the sinking of the fourteen gun sloop HMS "Lizard" which was wrecked with the loss of over one hundred crew. On 18 March 1967 the world’s first major oil pollution incident occurred when a supertanker, the "Torrey Canyon" hit the Pollard’s Rock, tearing a gash in her side and spilling 860,000 barrels of oil into the sea. Westerly winds and currents caused the oil to pollute of the Cornish coast and of the Brittany coast. She now lies in of water. Large amounts of toxic detergent was sprayed on the oil in an attempt to disperse it and, along with the oil, accounted for the loss of much of the marine life and 15,000 birds. At the time it was the world's costliest shipping disaster, and to date, still the worst oil spill on the coast of the United Kingdom. The government was first petitioned for a light on the reef in 1826 (with no success), and a second petition in 1839 was supported by the British Channel ports, Liverpool merchants and the Chamber of Commerce of Waterford. A meeting held on 21 February 1840 in Falmouth declared the reef would shorten the route around the Isles of Scilly by up to 36 hours, and on 31 July 1841 a lightvessel (also known as a lightship) was seen at nearby St Mary's, Isles of Scilly. A lightvessel was first moored near the reef on 20 August 1841 and exhibited its first light on 1 September 1841.