Ofvious solution - navigate as man has for thousands of years. Use a sextant and compass. My goodness, if Vikings could find England, if Columbus could sail to America, if Polynesians could settle all the Pacific Islands, etc. why can’t modern man steer without GPS?
Captain William Bligh and a handful of loyalists, starving and weak, landed at a Dutch settlement in Timor, after traveling 3,618 miles on an open 23-foot boat. Bligh navigated using only a sextant and a pocket watch.
Crowded waters, traffic moving at 15+ kts, in both directions, limited room to manuever leaves little or no time to employ traditional navigation tools.
There is a lot of difference in navigation on open seas and a harbor.
In fairness to the present day navigators, the precision required to avoid Iranian waters is slightly harder than setting sail and heading in the general direction of England or “India” as the Vikings or Columbus did long ago. The Polynesians used the stars to navigate and the Hawaiian Islands extend over one thousand miles. Hard to miss them. (Hilo to Midway)