+1 from me - very interesting input. One correction worth making on the Bosphorus comparison though. The $1.7m-$3.5m per tanker figure doesn't hold up because supertankers in the 200-500,000 DWT range simply don't transit the Bosphorus. The Montreux Convention and Turkish physical constraints effectively bar the largest tankers from using the straits at all. Apply the $6.70/ton rate to vessels that never actually show up, and you get a meaningless number. Per-vessel fees for ships that do transit reportedly average $15,000-$30,000 - a very different picture. That said, the broader point stands and I think it's a fair comment based one which I have chanced my viewpoint to some extent - There is clear scope to charge maintenance fees to cover navigational safety, traffic separation schemes, piracy response, pollution incidents, and aids to navigation. The Malacca littoral states make exactly this argument, and it's hard to dispute - those services cost real money and somebody has to pay for them. The critical qualifier is that any such regime has to be implemented transparently and consistently, and cannot be used as a lever. The moment fees become discretionary tools of political pressure rather than cost-recovery mechanisms, the framework's legitimacy is destroyed. That's the line between Turkey's model - whatever its imperfections - and what Iran is currently doing.
