As the Ritz Carlton Yacht Collection's Luminara heads from Barcelona into the open Med, it’s clear that this midnight-blue vessel is fundamentally different than the larger, boxier cruise ships in the harbor. It has a svelte profile and sharp bow, very modern and yacht-like compared to the floating high-rises. But is Luminara really a yacht? That’s the question I wrestled with recently during the 794-footer’s “pre-maiden voyage”—the name given to our three-day excursion preceding the “maiden voyage” with A-listers such as Martha Stewart, Kiley Jenner, Tom Brady, Kate Hudson, Nina Dobrev and others. It’s a question that probably seemed irrelevant to the Instagram and You-Tube influencers in our media group who, in the middle of all this luxury, looked like they’d died and gone to yachting heaven. Still, it gave me the context to compare the new flagship of The Ritz-Carlton Yacht Collection, which joins sisterships Evrima and Ilma, with the conventional superyachts I’ve been writing about for..