divers who then dived to the bottom of the sea to gather pearls. In order to enable the divers to reach the bottom, two heavy stones were tied to the diver's feet and a chord to his waist. The chord end was held in the hands of those who were to pull him out. When the bag of pearls became full, the diver would signal to be pulled out with those who pulled having to remain alert to avoid the diver dying from a lack of oxygen. Decline of the pearling industry The Japanese cultured pearl, initially regarded as a wonder and shown at expos and other fairs, started to be produced in commercial quantities in the late 1920s. The influx of inexpensive, high quality pearls onto world markets took place alongside the economic impact of the Great Depression. The result on the Gulf's pearl markets was devastating. In 1929, 60 of Dubai's pearling boats (in 1907 there were 335 boats operating out of the port) stayed in port throughout the season. The complex system of financing that underpinned the pearling industry, the relationship between owners, pearl merchants, nakhudas (captains) and divers and pullers fell apart and left an increasingly large number of working men in the town facing destitution. In the 1930s, a record number of slaves approached the British Agent seeking manumission, a reflection of the parlous state of the pearling fleet and its owners. British empire: 19th - 20th century Ottoman attempts to expand their sphere of influence into the Indian Ocean failed and it was Portuguese expansion into the Indian Ocean in the early 16th century following Vasco da Gama's route of exploration that resulted in the sacking of many coastal towns by the Portuguese. Following this conflict, the Al Qasimi, a seafaring tribe based on the Northern Peninsula and Lingeh on the Iranian coast, dominated the waterways of the Southern Gulf until the arrival of British ships, which came into conflict with the incumbents. Thereafter, the region was known to the British as the "Pirate Coast", as Al Qasimi (to the British 'Joasmee') raiders based there harassed the shipping industry despite (or perhaps because of) British navy patrols in the area in the 18th and 19th centuries. A number of conflicts took place, notable between 1809 and 1819. Persian Gulf campaign of 1809 After years of incidents where British shipping had fallen foul of the