Thanks all for the discusion.
Sean GG post #2 came closest to what I am after, however I still haven't got what I need.
Can someone point me to the verification of the extent of US airspace and the applicability of the restriction.
Sean says it is 12 miles, someone else has told me it is 5 miles.
I have no doubt that if I was cracking along at VMO, 13 miles at 9000 feet off Long Beach I would be in a truckload of strife.
To my mind anywhere you are under the control or supervision of US controllers you should be bound by the restriction.
Maui