Important to note is that the biggest fish caught in the 50s and 60s seem to all be goliath groupers (also known as jewfish) and are now critically endangered and illegal to keep. I imagine they still catch some on these charter boats, but they are required to release them once they do.
The unfortunate thing is that no matter whether something is illegal or not, it can still be a victim of bycatch when fishing for legal species, and bycatch mortality is quite high. Bycatch is actually higher than actual catch by weight for some fisheries+methods.[1] It's not just what you eat, but where it came from.
And of course the word 'illegal' in the open sea, when you have huge nurse ships in international waters (that will not touch any port in the country) means nothing.