If you are in charge of a ship in a harbour and someone on board is sick, you must tell the medical officer of health if you think the sickness might be a notifiable infectious disease. You have to do this because it's your duty as the person in charge of the ship. If you don't tell the medical officer of health, you will have committed an offence against the Health Act 1956.

When someone on your ship is sick, you need to think about whether the sickness could be a notifiable infectious disease, which is a disease that the authorities need to know about so they can help stop it from spreading. You must notify the medical officer of health if you suspect this is the case.

You must take this duty seriously, because if you fail to notify the medical officer of health when you should, you will be breaking the law and can get in trouble for it.