The majority of the important ports that have been established for many years are located 50 to 100 km or more from the open sea in the deep-water estuaries of what are, for the most part, large rivers.
Amazibuko enqanawa amaninzi abalulekileyo enziwa kwiminyaka emininzi eyadlulayo abekwa kwikilomitha ezingamashumi amahlanu ukuya kwikilomitha ezilikhulu okanye ukusuka kulwandle elivulekileyo kumanzi anzulu echweba lomlambo kwinto zonke ayimilambo emikhulu.