Its irrelevant where the border is. The fact that the captain of the Cornwall had his ship out of eyeball range of his boarding parties meant that he couldn't give them close support. He should be court martialed for negligence.
Being involved with boarding parties in our Navy, during the VietNam
years, it was always comforting to look over your shoulder and see
the big "Warboat" about a kilometer away with some nice big bloody guns on it.

JG/FME