This verse talks of the ‘boats out of Carthage.’ However, the Hebrew Masoretic text says a different place, ‘Tarshish,’ commonly associated with Spain (called Tartessus by the Romans and Greeks).
So which is correct, the Greek, or the Hebrew? We don’t know.
However, it appears that Carthage is more in line with the words of the prophecy. You see, Isaiah 23:1 speaks the people in this city mourning the destruction of far-away Tyre, and the people from Tyre originally populated Carthage. It is logical that they would still have family and business connections and would be disturbed by its destruction.
On the other hand, Tarshish (Spain) was also under the control of Carthage, as part of their empire. So ‘boats out of Tarshish’ could fit for the same reason. It could be argued that both Carthage and Tarshish would mourn the destruction of Tyre!
At Isaiah 60:9 the Greek translators spoke of the ‘boats of Tarshish’ just like the Hebrew text. So is the reference to Carthage in Isaiah 23:1 an error in the Greek, or an error in the Hebrew? We don’t know, but either way it appears not to matter.