It is not really a 19.century gunboat politics thing… blush - in marine practice we don’t do things that way anymore. It has more to do with a “customary agreement” that forms the “minimum base” anybody who has “political and economic influence” can agree to… oceanic freedom is the core of free container trade that moves 90% of the goods all land cities of all nations need equally to flow freely - gun blasting interruptions are not welcome and rejected by mankind for good and practical reasons…
Even the biggest gorilla in the monkey cage of nations can not afford to stay without friends in a globalized container trade world. So nobody is “shooting this out in wild west way anymore” humanity made the last intent to do it that way between 1918 and 1945 - lead us directly to two world wars in a row and guaranteed mutual atomic destruction at the end - since then we have learned that cooperation is a better way to go…this is why the oceans are free and will stay free and nationalist jurisdiction can not be extended to it.
Nobody can step out of “good trade customs and neighborship behavior” anymore in a rabiatic xenofobic nationalistic attack - it is simply NOT CONVENIENT…this is what shapes the real law of the seas …
Practicability shapes the customary law of the seas
Law regulating entities out of jurisdiction is worth nothing in practice... law going beyond the customary law of the seas is worth nothing in practice...
At sea nobody gives actually a dime what exactly the “local national peddling detail rulebook might say or not say” because “peddling rules beyond the customary” can not be enforced in practice.
Foreign ships can not be expected neither to understand the language nor the local rules and even worse they are “out of jurisdiction by default” anyhow under the law of the seas as they count as territory of their flag state.
As always local authorities and buerocrats can write this simple fact of practical life in quite long and impressive legal chapters, that are nothing more then dead text, nobody really cares about, and nobody needs to care about, as it can not be enforced in practice, anyhow without disturbing the freedom of the oceans, what would be bad for business.
This is the difference between “pretention of the local authorities” and "customary marine law of the seas everybody acts along in practice ".
In marine business you do not care much about “national legislations” you care about the “agressiveness of the enforcement practice” which is quite different. It is obvious that the enforcement practice can not be agressive as this would shu away the ships what is bad for business.
In a very practical manner when you sit on a cruiseship you do not ask in which countries zone we are today - what might be their rules on gambling? Do i commit fellony when going to the casino?. You do not care, you do not have to.