I spoke to a couple doing a B2B and they were not testing for people doing B2Bs which I found surprising. 25% of the ship were doing B2Bs
They were not testing on board for passengers returning to the USA. Norwegian were testing on board, spoke to people at the airport. Also Princess I believe were testing. People were told to book tests at Barcelona airport so we have no way of knowing who had to quarantine in Barcelona.
Very few people wearing masks although the crew were all wearing N95s and it was recommended that guests wear them except in their cabins and while eating and drinking.