Chris, it depends on where you intend to sail...and which official greets you at the dock, to some extent. E.g. some of the officials in the French Antilles (that would be St. Martin, Martinique, Guadaloupe etc.) get pissy when a boat shows up with U.S. state registration (I''m assuming that''s the alternative you are considering...) while other times it isn''t a big deal. Most Caribbean island nations are accepting of any paper, it seems, so as to clear you in and have you visit the shops.
If you''re heading further afield, you might want to check with the appropriate official - usually the naval attache'' - at the nearest Embassies (not Consulates) of a few major stops along your route (e.g. France, Australia, etc.).
Sorry to preach a bit outside sailing boundaries, but you really should have mutually arranged wills as spouses. And that will convey property outside of probate, in which case documenting in one partner''s name passes ownership to the other. That plus a Power of Attorney -or- a simple, notarized statement from your wife, allowing you to operate the U.S documented vessel as you see fit, should be all you need to cover emergencies outside the U.S.