“The Usefulness of Navigational Aids and Aids to Navigation.”
Abstract
The equipment provided on a vessel that helps the ship’s navigators navigate safely is called Navigational Aids. Most of them are electrical or electronic equipment but still some equipment does not require electrical power for operation. Aids to Navigation are placed along coasts and navigable waters as guides to mark safe water and to assist mariners in determining their position in relation to land and hidden dangers. Each aid to navigation is used to provide specific information. Several aids to navigation are usually used together to form local assistance to the navigation system that helps the mariner follow natural and improved channels. Such aids to navigation also provide a continuous system of charted marks for coastal piloting. Individual aids to navigation are used to mark landfall from seaward, and to mark isolated dangers.
Introduction
For safe, efficient economic and comfortable travel of vessels in rivers, channels harbours and along lake and ocean shores navigational aids are necessary. The purposes of navigational aids are to avoid dangerous zone, follow a proper harbour approach and locate the port during the night and bad weather conditions. Aids to Navigation are placed along coasts and navigable waters as guides to mark safe water and to assist mariners in determining their position in relation to land and hidden dangers. Each aid to navigation is used to provide specific information. Unlike the roads and highways that we drive on, the waterways we go boating on do not have
road signs that tell us our location, the route or distance to a destination, or of
hazards along the way. Aids to Navigation System is intended for use with nautical charts, which provide valuable information regarding water depths, hazards, and other features that you will not find in an atlas or road map.
A virtual aid to navigation itself does not physically exist unlike buoys and beacons but comprises a signal broadcast to a location in a waterway. It can be described as digital information transmitted from an Automatic Identification System (AIS) station located elsewhere for a specified location without being itself present in that specified location or simply stated, as an electronic virtual marker of a hazard. The basic symbol of a virtual AiS aid to navigation looks like a diamond shape with a crosshair at the centre on ECDIS or radar.
The term “aids to navigation” encompasses a wide range of floating and fixed objects (fixed meaning attached to the bottom or shore), and consists primarily of:
- Buoys — floating objects that are anchored to the bottom. Their distinctive
shapes and colours indicate their purpose and how to navigate around them.
• Beacons — structures that are permanently fixed to the sea-bed or land. They
range from structures such as lighthouses to single-pile poles. Most beacons
have lateral or non-lateral aids attached to them. Lighted beacons are called
“LIGHTS”, unlighted beacons are “DAYBEACONS”.
Navigational Aids for Airport Applications
Different airports operate under different conditions. Smaller airports (in size and level of air traffic) may only operate during daylight hours meaning they require less additional guidance and support and may only need typical runway markings and airfield lighting. Larger commercial airports will be required to operate during the night-time hours and, therefore, are obliged to be sufficiently equipped with navigational aids to support take-offs, landings and manoeuvres. The various forms of Navaids all work in different ways to deliver the same result. ILS systems focus on ensuring a smooth and safe landing for all aircraft by offering accurate horizontal and vertical support during their approach and landing. Their function is critical during periods of low/poor visibility. DME systems utilize ultra-high frequencies (UHF) to receive and send signals to and from the aircraft, enabling it to calculate its flight position and determine a time-to-station value based on the time it takes for the aircraft’s DME transceiver to receive a response from the DME
station. NDBs are ground-based transmitters that support and aid aircraft throughout their approach by providing the direction to the airport from their current position on their flight deck equipment. VORs similarly enable the aircraft to determine its position from the destination using Omnidirectional signals from the VOR system. DVORs are specifically used during low/poor visibility conditions. TACANs are used primarily by the Navy (but are used for civil applications) and are a modern adaption of the VOR (and deliver the same functionality).
Navaids from Systems Interface
We can provide a whole package of tools to assist airports with the aerodrome
safeguarding, the design and preparation of instrument approach procedures, studies for the definition of equipment specification, and system design — complemented where necessary by sophisticated computer modelling techniques for surveying and selecting sites for navaids and the protection of ILS sensitive areas.
Navigational aids are a crucial piece of equipment used for assisting the safe and efficient landing of aircraft which need to locate their landing zone accurately during low light hours and avoid high risk/danger during their approach.
That’s why we ensure that our navaid equipment and systems accurately measure the distance of aircraft and transmit signals to inform on landing locations, track the position of the aircraft while it’s in flight to ensure it’s staying on course and assist the craft during its descent and landing process.
Navigational Aids essential item
Many of the early age navigation aids have become obsolete and ceased to be used but some are regarded as essential items and are still used on ships.
Aids to Navigation Systems
Depending on where you boat in America, you may see several differences in how navigational marks are coloured, numbered, or lighted. Regardless of the location, buoys and beacons are placed in very specific locations, to mark either a particular side of a waterway or some other navigational feature. The primary system in use is referred to as the “U.S. Aids to Navigation System”. The U. S. Coast Guard maintains this system in conformance with the International Association of Lighthouse Authorities (IALA), which is an international committee which seeks to ensure safe navigation, primarily through the use of common navigation aids and signals. The “LATERAL” system is the familiar RED RIGHT RETURNING system, meaning that on all navigable waters returning from sea, the red even-numbered marks are on the starboard (right) side of the channel and the green odd-numbered marks are on the port (left) side of the channel. Numbers on the marks ascend when travelling from sea to harbour — if you don’t have a compass and become disoriented on the water, you will always know you are heading upstream if the buoy numbers get larger as you travel.
Port Side Odd Numbered Aids
Port side numbered aids are green in colour, odd-numbered and may be lighted. Port side marks are located on the left side of the waterway as you travel upstream, and the buoy numbers will increase as you head upstream. (Chart depictions are shown next to the marks) Port-Side Buoys have a cylindrical above-water appearance, like a can or drum floating on its axis. Commonly referred to as “CAN” buoys. Beacons-Port side beacons have square marks attached to them, with two shades of colour and a reflective border.
Starboard Side Even Numbered Aids
Starboard aids are red in colour, evenly numbered and will be on your right side as you travel upstream. Buoy numbers increase as you head upstream, and may have a red light. Starboard-side buoys have an above-water appearance like that of a cylinder topped with a cone, pointed end up. The cone may come to a point or be slightly rounded. Commonly referred to as “NUN” buoys. Starboard-side Beacons have triangular marks attached to them, with two shades of colour and a reflective border.
Intracoastal Waterway
For the sea buoys that delineate channels off the coast of the United States, and for the Intracoastal Waterway (ICW), red is on the right (shore side) when proceeding clockwise around the U. S. from the East Coast to the Gulf Coast, or proceeding north along the West Coast. ICW marks are further identified by a small yellow reflector at the bottom of the mark. The same port and starboard marks shown above will look like the following.
Numbers on the marks ascend when travelling in this direction. Where the IALA-B and ICW marks meet, one must be very careful to observe the change in meaning by referral to local charts.
Conclusion
Navigational aids are a crucial piece of equipment used for assisting the safe and efficient landing of aircraft which need to locate their landing zone accurately during low light hours and avoid high risk/dangers during their approach. Everybody, both onshore and at sea, has a responsibility for improving our ship's safety level. Aids to navigation, also known as AtoN, are important tools of navigation that enhances safety and can act as good safety barriers. Aids to navigation help ship navigating officers in finding and safely navigating a narrow channel in a wide expanse of water. Virtual aids to navigation are the potential in enhancing safety and their use brings us several advantages. For the safe and efficient navigation of vessels, it is important that the vessels recognize their accurate position and maintain a fixed course. Aids to navigation are established to assist vessels in the wide ocean where landmarks are not visible, areas crowded with vessels with narrow channels and areas with dangerous obstacles. Vessels ascertain their positions by the lights shape of objects, colours sound and radio waves．
References
1. https://en.wikipedia.org/wiki/Navigational_aid
2. https://www.marineinsight.com/marine-navigation/virtual-aids-of-navigation-are-important-for-ships
3. https://www.boatus.org/study-guide/navigation/aids
4. https://www.tokokai.org/en/role-types-aids-navigation/
5. https://www.systemsinterface.com/products/navaids/
6. https://www.slideshare.net/bhavikpatel19196/navigational-aids
7. Class Note Provided by
Captain Md. Arif Mahmud
Assistant Professor
Department of Maritime Science
