How a Submarine Works (Detailed Explanation)

The history of the discovery of the submarine begins with Cornellis Drebbel from Germany who was the first to build a ship to sink under water. The ship was built in the form of a rowing boat, covered with leather that has a depth of 4.5 meters.

Followed by an American inventor named David Bushnell, who built submarines for use in the United States war of independence. Over time, these submarines were increasingly being developed using steam, gasoline and batteries.

Submarines are a type of ships that moves under the surface of the water. This ship is generally functioned for military purposes, and is devoted to science and is able to penetrate depths that cannot be reached by humans.

There are many types of submarines in the world. The submarine’s parts may be slightly different from one another.

The use of submarines is so important for a country, so we also need to know how these submarines work. The following is an explanation of how submarines work:

Buoyancy Force

The first method of how a submarine work is known as the buoyancy force, where this method of work has a function to float and sink a submarine in the water. When the submarine float, it works by moving the weight of water which is equal to the weight of the ship. This displacement creates buoyancy and acts against the force of gravity.

In the submarine there is also a ballast tank and a bonding tank. When the submarine needs to float, the ballast tank is filled with air so that the density of the ship is less than the density of the water around it.

Meanwhile when underwater, the submarine’s ballast tank is filled with water, so that the density of the ship is greater than the density of the water around it.


Hydroplane is a device that moves in the form of short wings and has a function to regulate diving. It works by moving the water past the stern and push up so that the submarine is pointing down.

Meanwhile, in order to make the submarine stay at the required depth, the submarine will maintain a balance between air and water in the balance tank which causes the overall density to be equal to the density of the water around it.

And after reaching the depths to explore the surroundings, the hydroplane will be straightened so that the submarine is more free to roam in the water at that depth.

As for returning to the surface, it works by pushing the water between the balance tank and the stern to maintain balance when the submarine comes to the surface.

Air flows from the air tube to the ballast tank and the water inside is pushed out so that the overall density is less than the density around it. The hydroplane will be directed so that the water moves up the stern and pushes the stern down so that the submarine rises upward.

In an emergency situation, the submarine can climb to the top quickly by filling the ballast tank quickly with high pressure air.

Secondary Propulsion

Secondary propulsion has a function for the submarine’s rotating motor. So the sub has a tail rudder in the water. This steering function is to turn right and left. Together with the hydroplane it functions to adjust the front and rear direction of the submarine.

Global Positioning System (GPS)

This system works when the submarine is working on the surface of the water. As for below the water level, this system cannot work.

GPS is one of the most well-functioning satellite navigation systems using as many as 24 satellites sending microwave signals to earth.

The signals received by the tool has a purpose to determine position, speed, direction and time. By entering the GPS destination, data will appear on the screen.


Submarines are also equipped with a navigation system called sonar, short for sound navigation and ranging. This system is used to determine the location of a target.

The way it works is by using underwater sound waves which then detect an object under the sea and measure the distance under the sea.

So sonar sends sound waves beneath the surface and waits for the reflected waves. In addition, sonar can also work to improve the inertial navigation system by identifying ocean floor features.

That’s how a submarine works so that it can operate well above and below the surface of the water.