What is Sequential Method of ballast water exchange and factors taken into account?

6. Propeller Immersion

The aft draft of the vessel in each sequence of ballast exchange shall be adequate to fully immerse the propeller. If, for a transitory period or in a specific sequence, 100% propeller immersion can not be satisfied, the sequence is to be identified in the Ballast Water Management Plan with a footnote documenting this limitation. The following is an example of such a footnote:

“At this stage of the ballast water exchange operations, the full immersion of the propeller is not possible. This may be considered satisfactory provided the ballast water exchange operations are undertaken in fair weather and sea conditions – such that the Master will be satisfied with the control of the vessel’s maneuverability, and that there is sufficient ballast capacity available at all stages of the voyage to enable propeller immersion in a reasonably short period of time should weather and sea conditions begin to worsen.”