Thanks to all who are responding.

To be very clear, what I am exploring is picking up a boat in So.
America and traveling fairly directly to the USA, but with brief stops
of a few days at several ports along the way. A stay of a couple of
weeks would be the longest I imagine in any foreign port along the way -
and that only if there were problems needing repairs, or if there were
severe weather impeding forward travel.

I would have, I expect, the pre-sale registration, a Bill of Sale to me,
the signed-over Title, and of course passports for myself and crew.
Should I arrange to have the Title submitted here in the USA before
departing SA? I've bought & sold here in the USA so I am familiar with
state to state issues. But if I do this it will be the first
buy-overseas-and-bring-home. Any suggestions on methods of preparing
documentation for smooth port clearance along the way welcome.