Re: Do I Need an EPIRB?
Lightening strike, fire, loss of your antennae, loss of your electrical system all would incapacitate your DSC VHF radio (the AIS part really doesn't matter for the purpose of this discussion - any DSC radio will offer the same benefit).
The beacons are self contained - they are not subject to whatever problems the boat might be suffering from. And, they can go into the dink, raft or drink with you.
PLB's serve important additional MOB functions.