Razlog za to je, da se lahko ista plovna pot uporablja za dostop do več pristanišč, ki oskrbujejo različne trge, in zaradi tega lahko isto plovno pot uporabljajo različne vrste ladij, odvisno od trga (suhi tovor, tekoči tovor, blago v zabojnikih ali v razsutem stanju, blago, ki je lahko nevarno, strupeno ali škodljivo).
The reason for this is that the same route could comprise several ports servicing various market sectors, and therefore the same route might be used by different types of ships depending on the market sectors involved (dry cargoes, liquid cargoes, containerised or bulk, goods that may or may not be dangerous, toxic or noxious).