What is the difference between VHF Channel 16 and Channel 70?
Short answer
Channel 16 is for voice distress, urgency, safety and calling; Channel 70 is for DSC signalling only, with no voice traffic.
Do not make voice calls on Channel 70. DSC calls and alerts are sent digitally there, then the follow-up voice procedure normally moves to Channel 16 or another instructed working channel.
Quick check
What is the difference between VHF Channel 16 and Channel 70?