Some have speculated, not O'Neill, that the draft of a swiftboat would have barred such a boat from getting near the Cambodian border on the Mekong, which I doubt.
Anyway, in "1970" actual incursions into Cambodia were permitted - but not when Kerry was there.
On H&C last night Colmes screamed at O'Neill about this. O'neill kept saying "read the next sentence Colmes" implying C was taking it out of context. Then O'Neill went on to say that he was in a different region in the waters around Viietnam that was in fact close to the Cambodian border but that Kerry was in the Mekong which wasn't.