I would fly in on the Port shroud but not higher that the national flag on the Stbd. shroud.
I agree, but that would mean my flag would be about 5' above the deck, doesn't seem high enough, even your diagram shows to the spreader. I hope I can raise the home flag.
BTW the correct ensign to be flown by vessels either registered in the BVI's or visiting the BVI's is a defaced red ensign and not the Union Flag. Mind you in my time in the BVI's I never remember seeing one flown as a courtesy flag, you could start a trend.