To cruise or not to cruise: That’s the question facing millions who love being at sea but are deeply concerned about increasing their exposure to COVID-19. Fortunately, the 3-year-old Costa Smeralda, one of the world’s largest ships, now provides a positive and affordable answer. Blending an affordable and appealing itinerary with limited-capacity restrictions that are part of an intense anti-virus operating campaign, Europeans have been flocking to its weeklong clockwise circumventions of the Mediterranean Sea. And now, Costa wants those living outside Europe to join them. Current weekly ports of call include Barcelona and Palma de Mallorca, Spain; Messina, Rome, and Savona, Italy; and Marseilles, France. Passengers can start and complete their voyages from any of these ports. Key to the vessel’s success is Costa’s vigorous pro-health policy. Though the 20-deck behemoth can host 6,554 guests, capacity has been reduced by more than a third. That’s opened up spacing that …