There is no "clearing out" of the USVI for US citizens. Clearing in at Great Harbor, JVD is usually pretty quick and painless but with the new requirement that ALL passeners present at C&I rather than just the captain I have a feeling you would want to get there at some time the US day boat aren't.

Travel is fatal to prejudice, bigotry, and narrow-mindedness, and many of our people need it sorely on these accounts. - Mark Twain