Marine Navigation Equipment on Modern Ships (Part 1)

Blog | April 28th, 2020

Before, a ship navigation officer had to take help of unconventional ways to plan and navigate a voyage at sea. Gone are those days. Present-day seafarers are trained so as to know the functioning and operation of all modern day navigational equipment that has made the journey at sea smoother and safer. With modern day facilities and automation, a ship today has several advanced navigation equipment systems which give accurate data for the voyage. Below are marine navigation equipment on modern ships.

Gyro Compass

It is used for finding the right direction. Unlike magnetic compass, gyro compass is not hampered by an external magnetic field.  It is used to find the correct North Position, which is also the earth’s rotational axis to provide a stable directional source. Its repeater system must be present in the steering platform for emergency steering.


The seagoing vessels depend on S-band and X-band frequency radar system for navigation as it can detect targets and display the information on the screen such as the distance of the ship from land, any floating objects (an island, rocks, iceberg etc.), other vessels, and obstacles to avoid a collision. It is a rotating antenna which discovers the surrounding area of the ship.

Magnetic Compass

The magnetic compass work in conjunction with the magnetic field of the earth and is the essential means of the direction indicating device. It is used to get a planned course for the voyage. This ship navigation equipment is usually fitted at the centre line of the ship on the monkey island.  A transmitting magnetic type compass is fitted so that the output can be displayed in the bridge panel.

Auto Pilot

The ship bridge layout is filled with equipment and tools used for navigation. The autopilot is considered to be one of the most effective bridge navigational equipment as it assists the human operator in controlling the ship by keeping the steering in autopilot, which allows them to concentrate on broad aspects of the operation. It is a combination of hydraulic, mechanical, and electrical system and is used to control the ship’s steering system from a remote location (Navigation bridge).

Automatic Radar Plotting Aid (ARPA)

Automatic Radar Plotting Aid (ARPA) displays the position of a ship and other vessels nearby. The radar displays the position of the ships in the vicinity and selects the course for the vessel by avoiding any kind of collision. This bridge navigational equipment constantly monitors the ship’s surrounding and automatically acquires the number of targets, in this case; ships, boats, stationary or floating objects etc., and plot their speeds and courses respectively. It also presents them as vectors on the display screen and constantly update the parameters with each turn of the antenna by calculating their nearest points of approach to own ship and also the time before this will occur.

Automatic Tracking Aid

Just like ARPA, automatic tracking aid displays the information on tracked targets in graphic and numeric to generate a planned layout for a safer and collision-free course. Usually, A large size target measuring 800 m or more in the circumference is considered as a landmass and not tracked. Echoes less than 800 m are deemed as targets to be tracked.

Speed and Distance Log Device

This bridge equipment on a ship is used to measure the speed and the distance travelled by a ship from a set point. By calculating the same, ETA of the ship is adjusted or given to the port authority and agent.

Echo Sounder

There are many modern ship navigation tools present on ship and echo sounder is one of the instruments which has been in the play from almost 100 years now. It is used to measure the depth of the water below the ship’s bottom using sound waves which work on the principle of transmission of sound waves and an audio pulse which will bounce off a reflecting layer, returning as an echo to the source.

Electronic Chart Display Information System (ECDIS)

ECDIS is a development in the navigational chart system used in naval vessels and ships. With the use of the electronic navigation equipment, it has become easier for a ship’s navigating crew to pinpoint locations, and attaining directions are easier than before.

Automatic Identification System (AIS)

AIS is also among the types of a navigation system which helps to pinpoint the location and other navigational statistics of ships. AIS uses VHF radio channels as transmitters and receivers to send and receive messages between ships which endeavours to fulfil a lot of responsibilities.

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