Originally Posted by gotchiguy
No I don't think so. Erin told me that between La Frette and MII you only see each other at 3nm....surely VHF range would be twice if not three times that?
Originally Posted by Erin
I suspect it should be better than that and I plan on fitting a better aerial to see. Boat to base station is regularly over 30 nm.
I had always assumed that AIS range would be the same as VHF since you are using the same system with same antenna etc but thinking more about it prompted me to check what sort of power AIS systems transmit at, I always assumed it was the standard 25W.
Most manufacturers don't seem to advertise this in there specs but a standard has been set, for class A systems the output is only 12.5W and for class B it's a measly 2W.
This would explain why 2 ribs with class B and comparatively low antennas don't see each other until fairly close.
But then it wasn't designed for seeing where your mates are at, it's for collision avoidance so the range doesn't need to be huge.
Apologies for drifting the thread from DSC to AIS but thought it was worth a mention in case others hadn't realised the limited power.