The depth of water helps get them access to the deepwater ports. However a deep water port is usually made up for the usage of very large and heavily loaded ships.
A port is usually an area or platform entered into from the sea, by vessels, boats, ships, which also allows for protected staging and anchoring or docking for these ships to load and unload consignments and continue up towards its destination. A deep water port, from its nomenclature can be suggested that is different from regular ports in respect of the depth of water.