It's strange how everywhere varies the rules. The portuguese here use there card for all travel within Europe only needing passport for the rest of the world. They even travel to UK with it, I've travelled with them when they've done it. No questions asked at passport control of them, they were just let through at Liverpool, on showing the card. Hard to fathom sometimes what the rules really are. My German daughter in law also travels between Germany and UK on hers. This may all change after January though.
I think your passport remains your travel document. Carry the A4 sheet folded up inside it. The immigration officer will expect it volunteered. One got cross with me when I failed to show my Aufenthaltserlaubniss in Munich.
Double check! If you laminate your Spanish NIE which is paper credit card size, it makes it null and void, maybe its different in Portugal, if you can it might be worth it, as it will be on your boat, which of course will be prone to damp.
Seems to be OK to laminate them here in the islands. Have applied for new one with fingerprints. Took weeks to get the initial appointment. Then the Forty day wait for the card has been extended because one of the two office staff that's doing them has gone on maternity leave. The joys of island life!
A very good question. Only wish I had a really good answer.
Are you planning to leave the Schengen Zone in the near future
As a resident in Portugal you shouldn’t have problems travelling between Portugal and the U.K.
I don't know if it's mentioned in the info but when you register the first time you need to create a password in SEF. You must have a capital, a lower case, a number and a "special character like ! or£ " in that password or it just rejects it. I fell for that one and got a bit frustrated. Once you've got in its easy and you download a pdf certificate that you can print out.