CONAKRY (AFP) - About 30 people were believed to have drowned after an overloaded boat sank off the coast of Guinea, as rescue workers said Saturday they had given up hope of finding survivors after an all-night search. “We are continuing the search without hope of finding survivors, that means about 30 are already dead,” rescue official Lanfia Camara told AFP. “It is difficult and even unthinkable that we could find a survivor in the water after more than 15 hours without rescue. None of the passengers were wearing a life vest when they boarded.” The pirogue, a flat-bottomed boat used by fishermen and for transport, capsized a few minutes after setting off for Kassa Island which lies several kilometres (miles) from the capital Conakry on Friday.