Last week anyone who happened to be sailing with Explora Journeys in the Mediterranean had a brief chance to encounter tennis superstar Jannik Sinner, on board Explora II sailing between Genoa and Marseille for an overnight stay to promote his wellness collaboration with the cruise line. Sinner participated in a Q&A session and charity gala dinner, and made appearances at private coaching and wellness sessions available to a few select guests. No word on whether he’ll make further appearances but, as brand ambassador for the cruise line, I expect he will. Jannik Sinner aboard Explora II. Many cruise lines, however, have special guests on board who, while they mightn’t have the same celebrity status, are equally experts in their field.