Last week the International Maritime Organization came a step closer in the completion of the long awaited international Convention on the control of Harmful Organisms in Ships' Ballast Water. Intertanko participated at the specially convened meeting of the Ballast Water Working Group where over 180 delegates representing member states and NGOs upheld the IMO's spirit of compromise in discussing and agreeing on some of the main principles of this difficult Convention. The nature of the ballast water problem has meant that new ground has had to be broken by the IMO in taking into account absolute levels of control to ensure effective regulations which would cope with the science of biology - past Conventions have mainly focused on the chemical and physical aspects of marine pollution.