Boat Flags

what is the regulation concerning the flag you fly on your boat?

is there any difference beetwen sea and inland waterways ?
If i m a US resident with foreign nationality, my boat beeing registered in the States, do i fly my country s flag or a US flag ?
Thank you for giving me any web link on the subject

Outside territorial waters, we usually fly no flag. Put the flag of vessels registery and flag of countrys waters you are in up when we pick up the pilot unless near Iran; they want their flag up anytime we’re in their territorial waters. Inland is the same. Your nationality doesn’t matter, just where the vessel is registered.

Boat Flags – Remix!