Excellent point, hellosailor... I was involved with a lot of deliveries of foreign flag vessels into and out of the US from north and south and being a dual citizen could use either passport but was careful to use the same one for entry and exit... if you cross them up, it causes a long delay and a lot of explaining. I was always careful to use my US passport delivering a foreign flag vessel into the US because of the requirement to get a cruising permit
for the boat or if I was cruising my own vessel which was US flagged and documented.
On deliveries, I used a Letter of Permission from the owner (standard form letter I got from Donna Jenkins, Marine Documentation
lady in San Diego) on all deliveries, whether US or Foreign flagged.
I had a couple of instances where I needed to remove a US flagged vessel which was lying out of country from USCG documentation
because it had been bought by a non-US buyer then register it in another (third) country, bring it into the US and get a cruising permit
, then turn her over to the new owner who wanted to cruise
US waters. I drove one of them in the US for the new owner for some time at his request and was only boarded a couple of times, probably because of the foreign flag registry.
My biggest hassle was entering Canada
on my own boat from Washington
State with a South African, A Brit and an Aussie aboard. The Immigration guy accused me (in jest) of smuggling the United Nations into Canada
. My boat was US flagged so used my US passport out of and in to US waters.
My real puzzlement is under what law can the USCG board you in international waters that do not come under another country's sovereignty. Phil