Final answer:
Container ships have the ability to transfer ballast water internally among tanks to maintain stability during cargo operations, which allows them to avoid discharging ballast water.
Step-by-step explanation:
Container ships have two ballast operational behaviors that separate them from most other ship types. The first is the ability to transfer BW internally among tanks to maintain stability during cargo operations, in lieu of discharging/entraining ballast water.
Internal BW transfers provide a greater opportunity for containers to hold their BW without discharge, an accepted management approach that can enable them to avoid conducting BWE in many circumstances.