Much like aircraft, ships are a primarily safe mode of transportation, and your risk of death on board a ship is lower than in a motor vehicle. There are, however, potential sources of danger on a ship, including the risk of sinking. Most modern ships are designed to float in a wide variety of weather conditions and even after they have been heavily damaged, but no ship is unsinkable. As a passenger on board a sinking ship, you will greatly increase your chances of survival by remaining calm and following directions from members of the ship's crew.
The crew on board a ship are extensively trained in emergency procedures, including what to do in a situation where the ship appears to be sinking. If a ship seems to be at risk of sinking, a number of actions by the crew are set into motion including initiating passenger evacuation and alerting emergency rescue services to the fact that there is a problem. Modern ships are outfitted with lifeboats stocked with necessary supplies, and passenger cabins have life vests for everyone on board the ship as well. If you keep your head in an evacuation situation in which you need to leave a sinking ship, things will probably turn out well for you.
To maximize your safety on board a sinking ship, start by paying attention to the safety briefing given at the beginning of the voyage. Every ship is slightly different, so even if you have traveled by ship before, make sure to listen carefully to what the crew member giving the briefing has to say. During the safety briefing, the crew member will tell you where in the cabin you can find a life vest, and what you should do in an emergency situation. You will also be given a lifeboat assignment, and told how to reach your lifeboat. Do not be afraid to ask questions during the briefing to ensure that you know what to do in the event of a sinking, and after the briefing, familiarize yourself with the location of your lifeboat and your life vest.
Make sure that you know how to find your lifeboat in situations of reduced visibility such as those which might be caused by a fire. You can also usually find a safety information card or poster in your cabin: read it carefully and make sure that you understand all safety procedures. You should also try on your life vest to make sure that it fits properly and you understand how to put it on in an emergency. If the life vest looks damaged or does not fit right, request a new one.
If an evacuation of a sinking ship is ordered by the captain, follow the safety procedures which were outlined in the safety briefing. If a crew member gives you directions, follow them. Make sure to dress warmly in sensible clothing and shoes which will allow you to move freely, and wear your life vest over your clothing. Proceed in a calm and orderly fashion to your assigned lifeboat, and assist disabled passengers in boarding the lifeboat, if necessary. Once you are in the lifeboat with the crew members assigned to it, follow their orders.
Your lifeboat should contain stocks of food and water, flares, blankets, and communication devices. Most modern lifeboats have homing beacons that can be activated once the lifeboat is lowered into the water, helping emergency services to find you. Staying calm and helpful will help keep everyone in the lifeboat relaxed until assistance arrives.