I worked as a volunteer in Hong Kong for 16 years. The group I was with housed and rehabilitated heroin addicts. Hong Kong has had an opium/herion problem since the days of gunboat diplomacy. Anyway, I was told that the main way heroin came into Hong Kong was that it was tied to the bottoms of the hulls of a ship. Divers would go into the water and retrieve the heroin. I am sure this method is used elsewhere in the world. I wonder how the Coast Guard inspects the whole hull of a ship?