You've said your "I dos," you have your first mate, so now it's time to sail off into newlywed bliss aboard a luxury honeymoon cruise. But cruising is for cheesy Hawaiian-shirt-clad retirees, right? Think again. Each of these stunning ships is packed with once-in-a-lifetime amenities, like ultra-romantic rooms (many with private balconies), Instagram-worthy cuisine, full-service spas, and to-die-for destinations.We hand-picked these bespoke cruises for their unrivaled access to undiscovered cities and deserted beaches, their diverse range of romance-packed excursions, and their opulent onboard set-ups guaranteed to make you feel like a celeb. Best of all, with minimal planning necessary — the logistics of destinations, activities, and excursions are already mapped out for you! — cruising is the ultimate stress-free honeymoon. (And seriously, after all those guest list battles with your in-laws, who needs more stress?)If you've never set sail before, here's what you need to know: Cruise experiences can differ greatly on a small ship (fewer than 500 passengers), a midsize one (500 to 2,000), and a large one (more than 2,000). If you and your hubby crave energy, people, and nightlife, choose a large vessel, which will have multiple bars and restaurants, plus often a casino and theater for movies and live shows. If you prefer a sense of community and intimacy, stick to smaller boats, where you get to know your fellow cruisers (but also have less privacy, so plan alone time when you're in port).