Most people know that falling off the back of a cruise ship is a dangerous situation, one that can easily lead to tragedy. But what would actually happen if you were unfortunate enough to fall off the back of a cruise ship?
In most cases, the person who falls off will not be able to survive in the cold open ocean for very long. Depending on the season and location, water temperatures can range from a few degrees above freezing during winter in colder parts of the world, to a comfortable temperature during summer in warmer climates. In any case, a human body will rapidly lose heat when submerged in water and will eventually succumb to hypothermia.
The second major factor is the risk of drowning. Depending on their swimming ability and the condition of their clothes, a person could drown within minutes if their clothing drags them down or they become too tired to keep swimming. Even if they are able to stay afloat initially, exhaustion may soon set in as they battle against choppy seas and strong currents for hours or days before help arrives.
The third factor is the risk of getting struck by passing ships or other vessels. With hundreds or thousands of ships plying international waters at any given time, even in remote areas there is always a chance that one might come close enough for its wake or propeller to cause injury or death.
Finally, there is always the risk of being eaten by sharks and other predators that may be lurking beneath the surface. Although this is rarer than the other risks mentioned above, it is nonetheless real and should not be discounted entirely.
Conclusion: Falling off the back of a cruise ship can have potentially catastrophic consequences due to hypothermia, drowning, collision with other vessels and predation by marine life. In most cases it would be very difficult for someone who fell overboard to survive without immediate help from other ships or rescue personnel.