No, this doesn't work. (At least, it doesn't always work. I don't know
if it works sometimes, or never. It depends on the relative order of
execution between people on the ship and people in the province.) The
problem is that you might execute your MOVE <ship> order before the
captain leaves the ship, and then you will WAIT TIME 1 while he leaves
the ship, does his business, and reenters (all on the same day).
WAIT UNIT <ship owner>
This does work, as I originally mentioned.