Advantages of AIS
- The system is fully automated with absolutely no human intervention.
- Unlike Radar, It is not affected by rains or Sea.
- Its propagation is better than that of radar, due to the longer wavelength.
- It’s possible to “see” around bends and behind islands if the land masses are not too high.
- Additional safety at night time.
Limitations of AIS
- The system coverage range is similar to other VHF digital applications which depends upon the height of the antenna. Typical Range 20 NM.
- With the help of repeater stations, the range can be increased.
- Some vessels like fishing vessels leisure craft and vessels below 500 GRT may not be fitted with AIS.
- Accuracy of the info received is only as accurate as what is entered in the static/voyage or safety messages data.
- The OOW should always be aware that AIS fitted on other ships under certain circumstances, can be switched off on the master’s professional judgment.