Seafarers and especially those working in fishing vessels are at a considerably greater risk of injury than those working ashore. This chapter reviews the major causes of injuries at sea and identifies some of the preventative measures that are available. The problems of managing injuries at sea are considered.

 There are inherent differences between injuries and diseases. These are important when looking at their causes and when trying to analyse their frequency. Injuries are in general sudden events, normally caused by some form of release of energy, whether gravity in a fall, or from a falling object, kinetic energy when hit by a projectile, or trapped by a winch, heat energy in a burn. Chemical agents may also cause corrosive effects or result in acute interference with the functions of the body from toxicity. Some forms of injury can be cumulative, for instance repeated musculoskeletal trauma leading to pain and limitation of movement. Both toxic effects and chronic trauma lie at the borderline between health effects and injuries.

 Because of their instantaneous final cause, the place at which an injury happens, or the task being performed when it happens, is normally used as the basis for classifying it, and hence recording it, as an event. However, the antecedents to an injury may be distant from its scene, for instance as a consequence of design failings in equipment, or because of fatigue or impairment of the injured person or one of their fellow crewmembers.

 This chapter does not set out to be a comprehensive treatise on injury at sea. Its aim is to give readers an overview to enable them to participate in discussions and joint problem solving with others working in this field.