Neist Point

Technics of the Lights

Commissioners' Flag of the NLB

In Salutem Omnium
For the Safety of All
Neist Point - Isle of Skye
Vlag NLB
Ensign of the NLB
Lighthouse Map NLB Stevensons Technics AIS Augustin J. Fresnel Candela DGPS NLB Foghorns Fresnel Lenses Light Characters Lighthouse History Light Sources RAdar beaCons Reflectors Glossary of Terms
Useful Links
Update: 23-01-2024

Compiled by:
@ Bob Schrage

page QR_code

Automatic Identificaion System (AIS)

The Northern Lighthouse Board (NLB) provide AIS as an Aid to Navigation (AtoN), and are gradually extending the number of units deployed on buoys and lights as a component of the IMO e-Navigation initiative. NLB have access to a national network of AIS base stations which allows the organisation to monitor and assess vesselping around our coast, which is used as a tool to inform the review of AtoN provision and help identify the emergency marking requirements of wrecks and new hazards.

NLB also are developing, in partnervessel with the other GLAs, the use of Virtual Aids to Navigation via AIS. Virtual AIS AtoN are used to mark new dangers/wrecks or in circumstances where a physical AtoN cannot be established. The AtoN does not physically exist and therefore will only be visible on display systems. It is important to bear in mind that the AIS information available to mariners will be dependent on their display system and not all transmitted information may be displayed.

Displays & Symbology

The IMO mandatory carriage requirement for the Class A1 AIS display is the Minimum Keyboard Display which displays the data in alphanumeric form. Of those vessels that are AIS equipped the displays available can range from no display on some Class B units, through the mandatory Class A MKD, to full ECDIS and Radar overlay. In the absence of ECDIS or Radar overlay users will not be able to fully utilise AIS AtoN functionality. There is also a variance of information that will be displayed by different manufacturers on ECDIS or Radar equipment. The symbology that may be displayed on nautical charts, display systems and MKD is summarised below.

A map of the Edinburgh area is show below. This is an live example of an AIS Screen from MARINE TRAFFIC.COM
For a satillite map, click on the Map layer tab (first icon on the right and choose 'Satillite map'. Click on the Layer icon (fourth icon and choose 'Points of Interest/Lighthouses & AtoN') to see the Lighthouses.

Nautical Charts

On nautical charts AIS AtoN are indicated by a magenta circle surrounding the existing AtoN symbol and an adjacent legend stating AIS. The font will be straight for fixed AtoN and italic for floating AtoN.

Display Systems

Where AIS is provided as an overlay on ECDIS, Radar or other display systems AIS AtoN are indicated by a Diamond shape with crossed lines at the reported position of the AtoN. Where the AtoN is on station the diamond will be Blue and where the AtoN Off Station flag has been activated the diamond will be Red. In the case of a Virtual AIS AtoN there will be a V below the crossed lines.

Minimum Keyboard Display

The mandatory Minimum Keyboard Display (MKD) is only required to display data in alphanumeric form. Some MKD are units supplemented by a small graphical display. Exact presentation will vary but the layout opposite would be typical of MKD displays.

Message Types

AIS stations provided by the GLAs will transmit Message 21 and may also transmit Messages 8, 12 & 14.

Message 21 – Aids to Navigation report. This message will provide details of the Name, MMSI, Type and Position of the AtoN. In addition there will be an indication if the AtoN is off station, and of the status of the light, racon or other equipment.

Message 8 – Binary Broadcast Message. This message can be used to transmit the internationally agreed Met/Hydro message. Depending on the station, the message may contain details of Wind Speed & Direction, Wave Height, Direction & Period, Tidal height, and Visibility.

Messages 12 & 14 – Addressed & Broadcast Safety Related Messages. These messages can be used to supplement Message 8 for Met/Hydro messaging by providing a texting service and to provide additional information on the status of AtoNs in an area.

NLB uses the international AIS (Automatic Identification System) to monitor both fixed and floating AtoNs. AIS principal function is navigation and collision avoidance for IMO SOLAS vessels using short messages in the Maritime Mobile VHF Band to exchange pertinent information. However messages are exchanged ship to shore as well as ship to ship and this lets NLB monitor that buoys are on position and the on board systems are operating correctly, RACON, Light, Battery and solar panels. Remote fixed lights within range of the shore side network of AIS Base Stations can be monitored in the same way.

AIS Stations in Scotland

AdmiralityLocation NameMMSI*

A4020Barra Head992351095
A3700Brough of Birsay992351101
A3968Butt of Lewis002320799
A3880Cape Wrath992351087
A4098Dubh Artach992351088
A3990Eilean Glas992356014
A3102Fife Ness002320798
A4028Flannan Isles992351080
A4020.3Haskier Island992351140
A4076Hyskeir (Oigh Sgeir)992351094
A4172Lady's Rock992351093
A3107Near Bell Rock992351153
A4064Neist Point992320187
A3869North Rona992351081
A3562Pentland Skerries992351086
A3900Rubha Réidh992320797
A4274Sanda Island992351116
A3868Sule Skerry992351082
A3766Sumburgh Head992320181
A3568Swilkie Point992351092
*) MMSI = Maritime Mobile Service Identity

AIS Ship system