> extortion

not really; you would have to pay to run an oil pipeline through another country's territory even if that country wasn't bearing the cost of maintaining the oil pipeline

the strait isn't international waters -- it's part of Iran and Oman's territorial waters

> There are no maintenance costs for the open sea.

There are massive maintenance costs for the open sea with how we utilize it. Maritime security and policing, navigational infrastructure, weather reporting, radio repeaters, international bureaucracy, etc.

Global maritime trade is extremely costly. It's simply hidden behind opaque public spending on things you don't think about. In all likelihood it's a sunk cost that would ballpark around a few hundred billion dollars annually, invisible money spent just to keep things running at the scale and reliability that they do.

Now the maritime traffic passing through the Strait of Hormuz may only partially overlap with this spending, but people greatly overestimate just how "cheap" maritime activity actually is.

I don't think this count as open sea. The rule is 12 miles from the coast (12 nautical miles btw, i don't know what it is in freedom units). i'm pretty sure the strait is narrower than that at the place where the toll is paid (if you count both side, i.e less than 24 miles Between Oman's peninsula i forgot the name of, and Hormuz/Qeshm islands).

So basically, Iran say "here, you have to pass through our or Oman's waters, we will let you, but please pay a toll for the derangement, that we will share with Oman."