Thanks for the reply, Heidi.
This is very interesting. I have asked lots of people, and no one seems to know the answer. I know I am considered within the EU while visiting Schengen countries (the last is five days in), what I don't know is how immigration control, with their moody looking army type guys sitting in their little booth at Alicante airport (on my return), will know 24 hours after I left Lanzarote without an EU passport stamp, I did not leave the EU without a stamp and arrive in the US some 104 days after I arrived in Spain (without ever knowing I was on a cruise, because no stamps were provided until I got to the US)