This book provides rapidly accessible guidelines for dealing with medical emergencies in a small boat or yacht at sea. It is not a comprehensive textbook on first aid and it is strongly recommended that all seafarers should receive general training in first aid. Responsibility for first aid should be given to a nominated and appropriately trained member of any crew. The environment of the vessel and the sea imposes major limitations upon what can be achieved in the care of illness or injury while afloat. First aid treatment that may be appropriate ashore has to be modified at sea.