They didn’t wander into the waters off the coast of Iran. They wandered into the zone around Farsi Island. It sits in the middle of the Persian Gulf.
Middle of the Persian Gulf is a far way from the southern coast-line. The islands are a little more than half way across the Gulf. Again, tide currents prohibit drifting/wandering north. . .north by about 17 miles precisely on a course that would take them withing Iranian waters (3-miles) is not logical nor supported by tide currents.
Having spent 6-months aboard the USS LaSalle back in the later 80’s, being under way all around The Gulf, it is not reasonable to me that they entered Iranian waters. Heck, soon after departing Kuwait we found ourselves under way not making way and we didn’t drift north at all.
There's no neutral territory in the Persian Gulf. You're either in Iranian territorial waters or Kuwaiti's or Saudi Arabia's.......
Farsi Island belongs to the Iranians and they even have a very small naval base there........