Breathable linen tops, packable jackets, and cocktail dresses that go the distance. Surely the top reason to book a cruise is the ease of several vacations in one, with everything you need on board and excursions woven into your itinerary so you don’t miss out on any passing wonders. Possibly the only thing your ship’s crew can’t help you with, however, is the packing before you board. If you’ve booked the kind of cruise with an infinity pool and plenty of restaurants, there are some essential items that you’ll almost definitely need to include, from a comfortable swimsuit to after-hours outfits. From there, it gets a bit more specific, depending on your tour of choice . Have you signed up for an adults-only ship that centers fun, sun, and free-flowing Champagne at happy hour? Or an otherworldly journey to Antarctica ? Because these have very different wardrobe requirements, we’ve broken it down to make it as easy to pack as possible.…