Sperm whales are the largest of all toothed whales (which include dolphins and porpoises) with males sometimes exceeding 60 ft in length and females up to about 40 ft. They feed mainly on giant squid which occur most abundantly in the deep waters of all oceans. Sperm whaling was therefore carried out mainly from vessels operating some distance off shore or over the deep submarine trenches which approach the New Zealand coast at various points. Sperm oil and the spermacetic wax, which was once in such great demand for high-quality candles, are the main products of this whale, with ambergris (used for perfumes) as an occasional but formerly very valuable by-product. These whales were the primary quarry of pelagic sailing ships from 1791–1880, but have never formed a significant part of the catch of New Zealand shore stations. They are still hunted in the Antarctic Ocean, the North Pacific, and off shore from South America, but in the waters off New Zealand relatively few were caught after 1850 and only a negligible number after 1880, until the development in 1963 of a shore-based sperm whale industry in Cook Strait. This ended in 1965.