3 types of water transport:
rivers and canals, i.e. called inland waterways.
coastal shipping, i.e. moving materials from one port to another along the coast.
ocean transport, i.e. across the major seas.
River transport is often associated with smaller loads and narrow boats/barges. Some river systems can carry ocean-going ships for surprisingly long distances.
Some countries are fortunate enough to have a coastline that can be used for international transport, and cities such as Rotterdam, Hong Kong and New York have developed huge ports. The world’s 20 biggest ports handle over half of all world trade.
Sea transport is restricted to ports and journeys from suppliers and to customers need a change of mode, even if they are close to ports. Cargo movement is relatively slow, and needs time to consolidate loads and transfer them at ports. The low unit costs makes sea transport the most common international transport.
General cargo ships, also knwon as multi-purpose vessel (MPV) are built with cargo holds that possibly carry many variety of appropriate cargo. Most of these are loaded by crane, although some have side doors that allow vehicles to drive on and off.
Bulk carriers carry large quantities of cargo in bulk, e.g. grains and iron ores. Bulk essentially means 'not in packaged form'.
Tankers carry liquid or liquefied cargo, i.e. but by far the biggest movements are oil and liquefied gas. Economies of scale principle explains why ocean going tankers are built as big as possible.
Container ships are specially designed to carry standard containers and their capacity is commonly rated in TEUs (20-foot equivalent units) or FEUs (40-foot equivalent units). A typical container ship carries around 5000 of these, with larger ones carrying 10,000.
Ferries are usually RO-RO (roll-on roll-off) vessels that carry road vehicles over relatively short distances. There are, however, longer RO-RO routes between, say, Europe and America.
Barges are towed or pushed by tug boats. These are used for shorter routes where sea conditions are fairly reliable, such as between the USA and Puerto Rico. They have the advantage of being cheaper to run than normal ships.
Dumb barge - barge without propelling machinery.