When you think of a sailor, the first thing that comes to mind is probably an image of someone steering a ship by the stars. While there’s no denying that this has been the mainstay of maritime navigation for centuries, things have come a long way since then. A common misconception is that there are only two types of navigation systems: GPS and the compass. This article aims to provide you with a comprehensive breakdown of all the major types of maritime navigation systems currently in use. Read on for expert insight into each system, its pros and cons, and examples of where it might be used.
What is a maritime navigation system?
A maritime navigation system is the combination of all the different equipment, sensors, and software that is used to navigate a vessel. It includes navigational equipment such as the compass, the gyro-compass, the GPS device, the radar system, and the Electronic Chart Display and Information System (ECDIS). The navigation system also includes various sensors that detect conditions and other vessels in the surrounding area, such as the depth sounder, water temperature, and salinity sensors, wind sensors, and the Automatic Identification System (AIS). Finally, it also includes the software that is used to monitor and control the various systems and sensors on the vessel. A maritime navigation system is used to navigate a vessel and will be responsible for displaying the vessel’s position, course, speed, and other important information and data. The system will also be responsible for alerting the crew to any changes or deviations from the predefined path.
Electronic Chart Display and Information Systems (ECDIS)
As far as maritime navigation systems are concerned, ECDIS is one of the big ones. Not only is it one of the most commonly used systems, but it also has a wide range of functions, including navigation, collision avoidance, station keeping, and dredging. ECDIS is a full system that will provide you with all the information and guidance you need, from start to finish, so it’s useful for all types of vessels, including commercial vessels, passenger ferries, cruise ships, and yachts. ECDIS is an integrated digital bridge system that uses information from a number of different sources, including radar, AIS, satellite imagery, and depth soundings, to provide a real-time picture of everything taking place in your surroundings. The system also uses a chart that’s been converted into a digital format.
Global Positioning System (GPS)
As far as maritime navigation systems go, GPS is probably the most well-known. It’s also a relatively old system, having been first tested in the ‘70s, and it was brought into commercial use in the ‘90s. GPS uses a network of satellites in low Earth orbit to determine a vessel’s location. These satellites send out radio signals, and the receiving device on the vessel records the time the signal was sent and received. It then uses the speed of light to calculate the distance to the satellites, which, along with the time, is used to calculate the vessel’s longitude and latitude. GPS is primarily used for navigation and position fixing. GPS systems come in a number of different forms. Position fixing can be achieved with the use of a handheld GPS receiver, a marine-grade GPS receiver, or a marine navigation system that has GPS as one of its main components. The latter two options will typically provide additional features and functionality.
Radar Navigation
If you’re familiar with the way ships were navigated in the past, you’ll know that it relied entirely on the compass. That’s not so today, though, and the most common type of marine navigation system (at least, when it comes to commercial vessels) is radar navigation. Radar was first used for marine navigation in the ‘40s and has been the go-to system ever since. A radar system consists of an antenna, a transmitter, and a receiver, and it works by bouncing radio waves off nearby objects and then measuring the time it takes for the waves to return. The system then uses this data to calculate the distance and relative bearing of surrounding vessels.
Marine Electronic Navigation
Marine electronic navigation systems (MEN) are gaining popularity as the industry’s preferred method of navigation. MEN use software that relies on a combination of GPS, gyro-compasses, depth sensors, and AIS data (amongst other things) to track and navigate a ship. MEN can also be used for surveillance, monitoring, and controlling operations on a vessel. The main benefit of MEN is its simplicity. It’s easy to operate and navigate, and it can be used on its own or as part of an integrated bridge system.
Global Navigation Satellite System (GNSS)
GNSS is the maritime navigation system that’s currently in vogue, having been brought in to replace GPS in the ‘10s. It’s currently used by 90% of the world’s commercial vessels, and it’s expected to become the standard maritime navigation system in the next 5 years. GNSS uses a constellation of at least 24 satellites to determine a vessel’s longitude and latitude. The satellites transmit precise time signals, and each vessel is fitted with a receiver that collects the signals and uses them to calculate the vessel’s position.
Radar-Based Maritime Navigation Systems
A radar-based maritime navigation system is a system that uses radar sensors to detect the position and movement of other vessels in the surrounding area. There are two main types of radar-based navigation systems: Vessel Traffic Services (VTS) and Automatic Radar-Blinding (ARBS). VTS is used mainly in highly trafficked areas, like ports. Vessels are fitted with Automatic Identification Systems, which emit identification codes that are picked up by VTS stations. Vessels are then monitored, and information about them is displayed on screens at VTS stations. ARBS is used for marine navigation in open waters. Vessels are fitted with a transmitter and receiver, which are used to detect other vessels. Vessels are identified by their International Maritime Organization number and their position is displayed on a screen (or console) on the vessel.
Latest Innovations in Maritime Navigation
Electronic Compass
An electronic compass is actually a type of electronic chart, but it is important to discuss it separately because it is such a valuable feature. A compass provides an accurate reading of a vessel’s heading, which allows the crew to get an idea of the vessel’s current direction. This can be extremely helpful when navigating to an unfamiliar area, or when operating in conditions that make it difficult to rely on visual references. Electronic compasses are usually found in modern vessels that have been equipped with a computer navigation system. Although the compass reading is the same, it provides a different type of information than a magnetic compass. Electronic compasses often feature autopilot functionality and can be a great option for larger vessels.
Course and Speed Recorder
A course and speed recorder (or CMR) is a type of navigation system that records all information about the movement of a vessel. It tracks the vessel’s speed, distance traveled, and bearing. Larger vessels with ECDIS or other types of computer navigation systems may have a CMR built in, but smaller vessels may require a stand-alone unit. A chart plotter is often included and synced with the CMR, allowing you to view the data on a chart. CMRs are an important tool for calculating the distance between points, as well as planning routes. They can also be helpful for monitoring vessel performance, especially in terms of fuel consumption. CMRs are a must if you are required to track your vessel’s position in real-time. This information is transmitted to maritime authorities, helping them to keep track of all vessels in the area.
Automated Identification System (AIS)
An AIS system is a type of electronic chart that displays information about nearby ships. It uses a transponder to send data to nearby vessels, as well as maritime authorities. Vessels that are equipped with an AIS system are required to transmit their data at certain intervals, providing nearby vessels with information about the ship’s name, type of vessel, position, and destination. AIS was created as a way to reduce the risk of collision in areas with high levels of traffic, such as ports and waterways. It also helps authorities keep track of all vessels in the area and can be helpful in crisis situations. An AIS system is most beneficial for vessels that operate in areas with a high level of ship traffic, such as coastal waterways and busy ports. It is also helpful for larger vessels that may experience problems with radio communication.
Conclusion
As you can see, maritime navigation has come a long way from the days of spotting the stars and using the compass. With all the advancements that have been made in maritime engineering, it makes sense that navigation would also evolve and become more efficient and advanced. If you want to be a successful sailor in the modern age, it’s important that you understand the different types of navigation systems and how they work. Only then will you be able to make the best use of them and navigate your vessel with confidence.