Book excerpt: These Guidelines for the control and management of ships' biofouling to minimize the transfer of invasive aquatic species (hereafter 'the Guidelines') are intended to provide a globally consistent approach to the management of biofouling. As scientific and technological advances are made, the Guidelines will be refined to enable the risk to be more adequately addressed. Port States, flag States, coastal States and other parties that can assist in mitigating the problems associated with biofouling should exercise due diligence to implement the Guidelines to the maximum extent possible.