Special marks
Special Marks are not primarily intended to assist navigation but are used to indicate a special area or feature, the nature of which is apparent by referring to a chart or Notice to Mariners
Above: Special Mark Class Two Solar Buoy
Special Marks are used in the marking of cables and pipelines, including outfall pipes and recreation zones. Data Buoys are also classed as Special Marks. They are coloured yellow.
The buoy illustration above shows a Type 2 configuration of buoy. These are approximately three metres in diameter and weigh approximately six tonnes excluding moorings.