That's fine for Saga customers, their very target market ensures that by the time the cruise industry is back up and running most of them will have been vaccinated anyway. Spain may well be right to pursue the same course, and I'm sure that, despite being in the EU it would be their prerogative to do so, though I can imagine some squealing and protesting from other EU nations. What's absolutely certain is they could impose vaccine certificates on third country arrivals, of which the UK is now one. This begs another question. At what stage do governments start allowing people to "jump the queue" and get vaccinated in return for a small consideration either through their national (with a small "n") health system, or for private companies to buy up and sell the public vaccinations? To do so will cause an unholy row in the UK, but not to do so would deprive many younger would be customers from booking their 2 weeks in the Spanish sun - cue another unholy outcry from those affected, not to mention the airlines and tour operators.