Q.AIS, RADAR, ARPA & VHF- which one should not be used for anti collision?

Answer 4 Answers

ARPA is part of RADAR can be used for anti collision.Radar is more reliable equipment for anti collision provided Gps,gyro.,log and AIS data is interfaced with radar .Radar bearing and range should adjusted correctly to get accurate CPA/TCPA.

AIS can be used as referance 

AIS (automatic identification system ) is not used for anti collision . AISidentify the target by its name , call sign,  ship sign ,navigational status and also indicate its course and speed.  

I guess it's vhf Not to us as anticollison device