They are coloured yellow, marked “ODAS” with an identification number, and carry a small plate showing whom to inform if the buoy is recovered.
Mariners encountering any uncharted yellow buoy should make an Obligatory Report giving the position, together if possible with the buoy’s identity code number. ODAS stations may be met with in unexpected areas, often in deep water where navigational buoys would not be found. The mariner’s initial reaction may be that the buoy is adrift and lost, but this is not necessarily so, and no attempt should be made at recovery unless the buoy is in imminent danger of being washed ashore.
The International Hydrographic Bureau issued an advisory note to fishermen and mariners in 2004, pointing out that drifting and moored data buoys provide valuable information to many communities, including fishermen and mariners.
