Coast Guard Documentation?
You still need to check with your state to see if they require you to "register" the boat also, even if it''s documented. Some states require that you do nothing if the boat is documented. Other states (such as Maryland where I live) still require that you pay a yearly fee and then you have to display stickers on the boat as proof. Note this is NOT the full state registration with state numbers and all -- simply a sticker to show you''ve paid the yearly fee.
This topic has been covered inside and out previously, so be prepared.