Note: The author was SeaDream’s guest on its first restarted sailing out of the Caribbean. It’s going to be tough for cruise lines to resume sailings in North America anytime soon. That, in a nutshell, is the takeaway from last week’s COVID outbreak on the very first Caribbean cruise since the start of the coronavirus pandemic. That’s how I see it, at least, and I’ve been following the cruise world for a long time. As the incident on a small SeaDream Yacht Club vessel showed, no amount of pre-cruise COVID testing for passengers is guaranteed to keep the illness off...