[admax88qqq]

I don't think it's as hard as you think to track ships. They're all tracked already

Government will adapt and just ban shipping vessels from visiting sanctioned countries, or create a vast make work agency to inspect cargo on ships that visited sanctioned countries.

[toolz]

and who is going to track those ships? The sanctioning country doesn't have the jurisdiction and likely doesn't have the resources to logistically stop it. The countries benefiting from the trade (both sanctioned and allied nations) have every incentive to allow the trade to happen if it can happen without detection - so who is going to stop it?