The more depth a barge has also means the more cargo it can carry. Again, there is a limit in some areas due to the channel or berth depth. The type of cargo a barge carries categorizes it still further. Some barges transport crude oils, others heavy or black oils like no. 4 and no. 6 and asphalt, still others carry clean oils like the oil for home heating or diesel fuel. Very light products like gasoline and naphtha is another category.
Chemicals are in a category of their own.
Edible products like soy bean oil, corn oil, molasses and tallow require special barges that can be easily cleaned. Then there are myriad dry and bulk cargos carried by barge, coal, lumber, construction equipment, grain and rice, containers, steel, sugar, sand and gravel and railcars to name a few. Each barge is is also classed by the waterways it is allowed to traverse. This could be oceans, coastwise, near coastal, lakes, bays and sounds and finally, rivers. A barge can be constructed single skin, double bottom, double sides or double hull which is a combination of double bottom and double side.