Dutch explorers too often suffered from collision with the many reefs along the western coast, a result of the warm Leeuwin current, that baths the western shores, and has a huge effect upon creating the favourable Mediterranean climate of the south west corner of the state. Abel Janzoon Tasman, for instance, was sent from Batavia to scout the size of the new continent discovered. By the mid 18th century, the whole of the Western shoreline of the state had been mapped to a reasonable degree of accuracy, although these maps were improved subsequently by the British explorers George Vancouver, Phillip Parker King and Matthew Flinders.