Do they ask to see your passport if coming from the USVI on a ferry?
Of course! And you will go through customs as well at the airport.
why would I go to the airport in BVI if traveling there on a ferry
At st Thomas airport everyone goes through customs, us citizens and all others. It’s a port of entry. If you are going to BVI you need a passport.
Are you trying to go without one? I guess I don’t get the question.
what if my passport is expired when i get there? they want let me off the ferry?
So to make this easy for you ...
1. You show a unexpired passport to get on the ferry in STT (obviously IF the ferry is running when you are visiting - the ferry is NOT currently running due to Covid) - if visiting for a day it can be a Passport Card but if staying for longer it needs to be a Passport.
2. You go through Customs and Immigration upon arrival in Tortola
3. You show your passport and go through Customs and Immigration to get on the ferry to leave Tortola
4. You go through US Customs and Immigration upon arriving back in STT
5. You go through Customs and Immigration at the airport (even if you have not left the territory - all visitors leaving St Thomas have to go through C&I) to fly back to the States - this can be a Passport, Passport Card or DL BUT a passport makes things quicker