Just been over to Portimão this morning and the largest cruise vessel I have ever seen alongside was in port.
Turned out to be the "The World" registered in Nassau, with some pretty impressive stats:
Tonnage: 43188
Passengers: 699
Crew: 343
Length: 196m
Draught: 6,7m
It is the largest vessel I have ever seen enter the Arade.
There is more about the vessel here
http://www.aboardtheworld.com/
If a 40 000 tonne plus can get into Portimão now, this bodes well for the future of cruise traffic for Algarve tourism.