The General Lighthouse Authority’s strategy is to provide an appropriate mix of both physical and electronic Aids to Navigation (AtoNs) for general navigation in our waters. These physical AtoN include lighthouses, buoys and beacons.
We provide over 200 navigation lights, ranging from substantial Stevenson designed structures containing lights of over 20 miles nominal range, to lit beacons marking ferry routes. The lights are distinguished by their colour and character:
Fixed
Continuous. For example, F.G (fixed green)
Flashing
On for less time than off. For example, Fl 5s (flashing one (white) light every 5 seconds)
Quick flashing
Flashing at a rate of 50-60 times per minute. For example, Q.R (quick red)
Group flashing
More than one flash. For example, Fl(3) R 10s (three red flashes every 10 seconds)
Isophase
On and off for equal periods. For example, Iso 8s (on for 4 seconds and off for 4 seconds)
Occulting
On for more time than off. For example, Oc 8s (on for 6 seconds, off for 2 seconds)
All lighthouses in our estate were automated in the second half of the last century and are monitored on a 24 hour basis. The emphasis now is on modernising the lights themselves and, in particular, converting those without mains powers to solar energy.
NLB currently provides 174 lit buoys. We also have a statutory responsibility for the inspection of approximately 650 third party buoys in our waters.
Pursuing a policy of using renewable energy sources, combined with a desire to reduce risk to the workforce, we completed solarising our statutory buoy inventory.
Our buoys conform to the IALA Region A model and comprises 6 principal buoy types:
Lateral Marks – for example, Port (red) & Starboard (green) buoys
Cardinal Marks – yellow/black marks depicting the safe side of any hazard
Isolated Danger Marks – red/black horizontal stripes
Safe Water Marks – white/red vertical stripes
Special Marks – yellow with an ‘X’ topmark
New Danger Marks – blue/yellow vertical stripes
As a general rule, reliance cannot be placed on floating aids always maintaining their exact positions. Buoy positions should therefore be regarded with caution, especially in exposed locations or after poor weather.
Buoys should generally not be used as a primary source of vessel position fixing but rather for situational awareness. In circumstances where they are the only source of visual positional reference, caution should be used. NLB buoys display their name and the NLB website address.
We currently provide 25 beacons around our estate. Beacons range from unlit/lit pole beacons to substantial, lighted structures for the purposes of leading lines, hazard and channel marking
The General Lighthouse Authorities’ (GLAs) Navigation Policy, requires that all aids to navigation meet the requirements of the present and changing needs of mariners. We therefore review AtoN provision on a regular basis to assess current and future requirements and undertake an operational review every five years.
Each GLA reviews the AtoNs in its own area of responsibility and joint consultations are conducted where there are areas of common or overlapping interest.
The last review was completed in 2025 and is published on the NLB website.