TheGuidelinesforBallastWaterExchange,underdevelopmentbytheOrganization,are expectedtoinclude,atanappropriatetime,thefollowingprecautionaryadvicetoMasterswhen undertakingBallastWaterExchangesequencesthatinvolveperiodswhenthecriteriaforpropeller immersion, minimumdraft and or trimand bridge visibility cannot be met:
1 Duringballastwaterexchangesequencestheremaybetimeswhen,foratransitoryperiod, one or more of the following criteria cannot be fully met or are found to be difficult to maintain:
.1 bridge visibility standards (SOLAS V/22);
.2 propeller immersion; and
.3 minimumdraft forward.
2 AsthechoiceofacceptableBallastWaterExchangesequencesislimitedformostships,itis not always practicable to dismiss from consideration those sequences where transitory non-compliancemayoccur.Thepracticalalternativewouldbetoacceptsuchsequencesprovidedan appropriatenoteisplacedintheBallastWaterManagementPlantoalerttheshipísmaster.Thenote wouldadvisethemasterofthenatureofthetransitorynon-compliance,thatadditionalplanningmay be required and that adequate precautions need to be taken when using such sequences.
3 InplanningaBallastWaterExchangeoperationthatincludessequenceswhichinvolve periodswhenthecriteriaforpropellerimmersion, minimumdraftandortrimandbridgevisibility cannot be met, the Master should assess:
.1 theduration(s)andtime(s)duringtheoperationthatanyofthecriteriawillnotbe met;
.2 the effect(s) on the navigational and manoeuvring capabilities ofthe ship; and
.3 the time to complete the operation.
4 A decision to proceed with the operation should only be taken when it is anticipated that:
.1 the ship will be in open water;
.2 the traffic density will be low;
.3 an enhanced navigational watch will be maintained including if necessary an additional look out forward with adequate communications with the navigation bridge;
.4 the manoeuvrability of the vessel will not beundulyimpairedbythedraftandtrim and or propeller immersion during the transitory period; and
.5 the general weather and sea state conditions will be suitable and unlikely to deteriorate.