In this supplement we discuss the use of medicines on board. This chapter includes the most important aspects regarding application, side effects and dosage. It has been decided to include the medical equipment in a separate supplement, because the medical equipment on board ships is subject to changes in international and national legislation. The changes can be quickly updated in this supplement. Another reason is ease of use. With this book you have a publication focused on equipment and medicines, in which you can quickly find what you need.The Medical Maritime Manual and its supplement are mandatory on board every ship at sea and are supplied bilingually: English and Dutch, very useful for the multilingual crew. Providing medical care on board Sailors are often deprived of conventional access to medical care on shore during their work. For this reason, providing medical care on board is an important area of attention. Training sailors to provide medical care on board, good medical equipment on board and telephone medical advice from doctors of the Radio Medical Service (RMD) contribute to the quality of medical care on board. A good medical manual, tailored to maritime navigation, is indispensable.