It is an international commercial custom that traded quantities of bulk cargo such as iron ore, coal, steel scrap, salt, etc. are determined by draft survey. In draft survey cargo quantities are computed based on the change of ship's drafts between the loading and unloading times by using the scales equipped on board the ship. This convenient method is universally adopted as the most efficient and reliable way of measuring the cargo quantities. We are confident of our draft survey technique and enjoy high prestige all over the world.