Focal Points Navigation > Limitations of electronic and other means of navigation
Multi Purpose General Cargo vessel > 3000 gt [2]
When sailing in areas such as Chinese waters, where every fishing buoy is fitted with AIS, it is tempting to think that every dangerous object is fitted with AIS. The Disciplinary Court wishes to point out that this is not a safe assumption. There are also many objects in the oil industry that have no power supply, are unlit and do not have AIS. There are also many small and even large ships around the world that do not have AIS or have AIS turned off.
As a result of this grounding, and in view of the increasing use of the Northwest Passage (NWP), attention is drawn to the importance of being familiar with (a) the CATZOC classification of the navigation area and (b) the limitations and uncertainties associated with low-category CATZOC areas (C, D and U). The significance of those uncertainties is not the same for every navigation area: particularly in shallow and infrequently navigated waters, discrepancies between the actual conditions and the available hydrographic data may constitute a significant safety risk. In deep water or in heavily trafficked waters, such discrepancies are generally less likely to result in an incident.