The only BNC socket connectors I remember were on Motorola GM300 ( or poss GM900) neither of which are normal marine base radio's. Sometimes seen as work (PMR) sets on cabin boats but not open boats. I think standard had a base set with BNC out about 15 years ago, I think it had a telephone style handset.
The TNC connectors I remember were on GPS units
I wish manufacturers would use N type as its a nicer connector, but I guess its cost and the difference between PL/SO 259 and N type makes sense and most its sort of a standard these days.