When does a passport receive an exit stamp when taking a transatlantic cruise from the Shengen Area?

I did the Carnival Celebration cruise from Southampton to Miami in November. I did not receive a stamp in my passport at all, not when entering London or in any of the ports in Spain or Portugal. On my previous trip to Europe, I had to ask for stamps upon entering and exiting at the airport as they weren't going to stamp then either. I think everything is done electronically now. Makes me sad, I love stamps in my passport.

We've done this return transatlantic many times, departing Europe in Barcelona and Rome (Civitavecchia port), with a final "European" port call at either Ponta Delgada or Funchal. We have never had our passports stamped during any phase of this trip. We were required to show it to the check in agent when we first board ship in Europe, but it is only scanned, not stamped. After that scanning, passports were not requested or required until we finally reached the US and went through the CBP checkpoint in the US. Hope this helps.

When is the passenger considered to leave Schengen? Is it at embarkation? I need to closely watch my 90 day limit.

A different context, but I know that owners/crews of private boats (think 30-60 foot sailboats) have issues with the 90 rule. Time at sea sailing from the continent to the Canaries or Azors is vague, and subject to interpretation by any given border agent. If they’re cutting it close, they clear into Gibraltar just to get out of Schengen for their days at sea.

I wondered the same thing We left Barcelona for the US by ship in December. There's no stamp in my US passport. Our last Schengen stop was 8 days later, Madeira.

We did it the other way around - Florida to Azores, Maderia, Cadiz. We weren't stamped into the Europe until we arrived in Barcelona. When we left (heading for Singapore) they retained our passports at boarding in Barcelona (not happy) and retained them until after we left Crete - which was the stamp we got.