You need to send an analyst there with binoculars, a box of cigars and $15k in cash to get realtime trustworthy data
or just a cubesat on a polar orbit with a Nikon Z9 inside
The strait is wider than horizon distance from reasonable heights. Also that's how you don't hear back from the analyst in many different ways.
Do these ships not use transponders? E.g., in the US you can use a SDR dongle and a RPI to read local updates. The straight isn't very wide.
Seems cheaper than the cigars and cash.