Communicate via written notes - although native speakers?

Question

In another forum I read the following amazing thing:

"In the middle 1980s, when I was in the Navy, the submarine I was in operated out of Holy Loch, Scotland. Our Xerox copier needed maintenance and the American Xerox tech was on leave. So a tech came out of Glasgow. I had a junior yeoman, an Alabama Black, escort the Glaswegian. The two of them were reduced to writing notes to each other. They had no trouble reading the other's written English, but the two accents were so strong that their spoken English was mutually incomprehensible. However, if you had asked either of them, they would have told you that they were speaking their native language, English."

Have you had similar (comparably extreme) experiences? Please, only native English speakers (obviously there are many examples from or with non-native speakers)!

Answer 1

According to this Washington Post article, the film Trainspotting, which is set in Edinburgh, had to have some of its dialogue redubbed with weaker accents for the benefit of American audiences (subtitles having been ruled out).

Answer 2

I once visited Edinburgh, and was unable to understand many of the locals. (I'm a native English speaker from Boston.)

Answer 3

I live in southern New Hampshire. I know a number of people, largely males in their 50s or older, who have thick New England accents that even some locals have difficulty understanding. I have not ever met, nor do I suspect I will ever meet, anyone who can do even a passable imitation of an old Yankee.

Answer 4

As a speaker of (I suppose) mid-Atlantic U.S. English, I once had a non-conversation with a New Yorker...