What Keeps a Cruise Ship Afloat?

By Alice Nichols

The concept of a cruise ship staying afloat is an often asked question. Cruise ships are massive vessels that require a great deal of energy to stay afloat. To put it simply, the buoyant force of the water keeps a cruise ship afloat.

A cruise ship is filled with large amounts of air and other materials that create an overall density that is less than the density of sea water, causing it to float. This is known as the principle of buoyancy. The amount of buoyancy provided by the water depends on the size, shape and weight of the vessel.

The way a cruise ship is constructed also affects its buoyancy. For example, if a vessel has a lot of open areas or has lightweight materials in its construction, it will float more easily than one with a heavier construction. In addition, if the hull is designed in such a way that it creates pockets for air pockets, it will also increase its buoyancy.

In order to maintain its stability, a cruise ship needs to have an adequate supply of ballast water in its tanks. This helps maintain its balance and prevents it from tipping over in rough seas or high winds. Ballast water also helps keep the vessel moving forward through waves and currents.

The engines on board a cruise ship are also essential for keeping it afloat. The engines provide power for propulsion and steering as well as power for electricity and other amenities on board the vessel. Without these engines, it would be difficult for a cruise ship to stay afloat and maneuver in open waters.


In conclusion, what keeps a cruise ship afloat are its design features such as air pockets in construction, ballast water tanks and powerful engines that provide propulsion and steering control throughout the voyage.