GeoffSchultz wrote:
and find no mention of any 22B/83B. I suspect that they're talking
about 22/83, but that doesn't explain why I can't hear the broadcasts
when I typically have great reception/range.

That is because these channels are full duplex channels where receive
and transmit are using different frequencies. The A and B designations
are to indicate ship frequency (A) or shore frequency (B).
If you set your radio to 'US' mode you'll get 22A only on channel 22
(transmit and receive on the ch 22 ship frequency) as this channel is
use by the US coast guard to talk to other ships.
If your VHF is set to 'International', then, if set to ch 22, it should
receive on ch 22B and transmit on ch 22A.

What is the make and model of your VHF ?

Markus