An increasing number of port states world wide require that vessels arriving in their waters should submit reports regarding their water ballast practice. The background for this is problems experienced with harmful aquatic organisms spreading from one area to another through a ships ballast water system.

Ballast water exchange at open sea is deemed as an effective way of prohibiting transfer of harmful aquatic organisms and pathogens to the arrival port.

Port states having requirements to ballast water management, will most often implicitly require a “Ballast water management plan” to be carried on board. Having such a plan will also give the following advantages:

• The plan gives information to the master regarding the requirements to water ballast reporting to different port authorities

• Delay in ports may be avoided, if a proper ballast water management routine can be documented to the port authorities

The plan gives assistance to the master in exchanging the water ballast in a safe manner

Exchange of ballast water in open sea may endanger the ships if conducted incorrectly. On this background, DNV offers the following services concerning ballast water management:

• Preparation of the "Ballast water management plan", both for the “sequential” and “flow-through” method.

• Calculation of acceptable intermediate stages of loading and unloading ballast water in open sea (sequential exchange of ballast water)