Exactly. The US just announces that they will take any vessel that pays for transit. So, what happens then? Any vessel that goes through and the IRGC doesn't shoot them, the US seizes. So, no one pays since they can't pay for successful transit. The fun game is that all the vessels just go at once. Any that the IRGC doesn't shoot the US takes. Any that it does shoot sink. So, no transit. Unless IRGC doesn't shoot at all, in which case everyone gets out of there with just one vessel paying the ransom. Ultimately this doesn't work for the IRGC as the US is far more capable of closing the strait than Iran is.
The US can also fuck with Iran by getting slight cooperation from ships in the Gulf of Oman by getting some small inflatable boats with remote control and AIS transmitters on them. Put the boat in the water next to a ship, turn of the ship's AIS, turn on the boats AIS, and send the boat through. Send hundreds of them. IRGC won't know what to shoot at or will expose their positions by firing at a rubber raft.
This is some wacky races shit that boils down to:
1. US fucks up by engaging Iran, Iran closes strait.
2. US fucks up the negotiations and fails to reopen the strait.
3. US decides to try and rescue its initial war goals, through a mutual blockade with Iran, starts sinking the very vessels it demands Iran gives passage to.
Does Mutley get a medal?
Or they'll use a pair of binoculars (or a drone with a camera) to ignore the decoys and shoot at the actual ship...
The horizon at sea level is about 3 miles. The strait of Hormuz is 35+ miles wide. Any mechanism used to get around this would be detectable and could be attacked with relatively inexpensive ordinance.
About 20 meter elevation would be needed to cover the navigable part of the strait. So, a couple of tall ladders?
Look at the map. They have mountains. Not much rain/fog in that area to block the sight lines. Maybe haze.