It’s the night before a long-awaited cruise to the Caribbean, and one question keeps running through your head: “What to pack, what to pack, what to pack?” You don’t want to underpack, and you certainly don’t want to overpack since you may need room in the suitcase to bring back purchases. You want garments that are neither too light nor too heavy, so that you can transition from the air-conditioned ship to the sunny skies at the port of call. Not to be forgotten are transitional pieces such as wraps and cover-ups that can translate from poolside to lunch to a casual dinner. Items that will stay wrinkle-free are ideal: Garments that can be rolled into a ball and layered in the suitcase by some tissue paper make it easier to zip off to a winter paradise vacation without worrying about hangers and garment bags.

Packing for a winter cruise getaway used to be tricky. But thanks to the influx of brands offering resort- and cruise-wear, the challenge has become an enjoyable one. This season, resort collections have taken off, with stores from Barneys and Saks to Key and Scoop offering selections of apparel and accessories from a wide variety of designers. This fast-growing category is responsible for the splash of color and Capri pants in some New York stores in the dead of winter, when the streets outside are a sea of cumbersome black wool garments.

Available in retailers from approximately mid-November through January, resort and cruise collections provide an opportunity to add new items to a wardrobe for a winter getaway, but can also provide timeless pieces that work year round. These collections aren’t just about flip-flops and 100% cotton garments. They also include silks, lightweight cashmeres, and fabrics like chiffon and taffeta that work well for a formal evening event. When purchasing these items, consider the versatility and wearability that the garments provide during your cruise, but also think about their use afterwards in the office or for a night out on the town.

Designer Michelle Smith has been designing resort-wear since she started her label, Milly, five years ago. Ms. Smith’s collections, which have been shown at New York Fashion Week for the past several seasons, are a great choice for cruising – perhaps because the designer goes to the Caribbean every year from Christmas to New Year’s. She says she creates garments for the line that she would want to wear during her own vacations.

Ms. Smith describes this season’s collection as “very exuberant, bright, and cheerful; reminiscent of Acapulco in 1960s, when it was a haven for the jet set, incorporating the colors of turquoise, coral, and then going back to brown.” She especially recommends a good pair of “traveling pants,” like her Italian stretch cotton twill pants. Milly features transitional pieces from cruise and back to reality, and is launching a “Cabana collection,” comprised of bathing suits and cover-ups, in January.

The couture swimwear company Gottex offers poolside attire, too. The brand was the first to introduce matching cover ups, creating a “complete cruise outfit,” in 1966. This season, designer Gideon Oberson was inspired by the Caribbean and vivid colors. The longer pareo wraps, or shorter sarong wraps, help make for a graceful transition to the lunch buffet from the pool deck, without having to resort to an old pair of gym shorts over your swimsuit.

One of the biggest dressing dilemmas for cruise-goers is formal wear. Almost every cruise has a “formal night,” and if you embark on a one-week cruise you can expect two during the course of the trip. Of course, attendance is optional, but, like the senior prom, it’s more fun to dress up and go than to sit in your room thinking about it. If you forget to bring formal attire, most cruise lines offer rentals, but you’ll look best in an ensemble you’ve chosen ahead of time. Most of the resort collections currently in stores offer feminine silhouettes and detailing, light, airy fabrics, and nautical themes.

Eve Gelade, the owner of Key, a new boutique that opened in September, recommends dresses by designer Corey Lynn Calter for cruises. One particular highlight is the “hostess dress,” which comes in jewel tone colors and silky satin fabric. Ms. Gelade points to crochet, lace, tunics, and denim gauchos as hot resort items.

Men can head to Scoop for one of J. Crew for Scoop’s button downs, or pick up a lightweight cashmere sweater by Habit or Michael Kors. J. Crew also has warm weather offerings that can be dressed up or down, such as blazers and pants. Barneys Co-Op provides some casual, cruise-appropriate attire by Marc Jacobs and Theory.

A few designers that are favorites of the jet set crowd, such as Ralph Lauren, Carolina Herrera, Vera Wang, and Chanel, provide resort-wear garments this season that you may find yourself incorporating into your wardrobe year round.

Ralph Lauren, as he often does, works with a classic nautical theme. This season, a pair of white pants, lightweight sweater, and matching handbag are good options for a day excursion and a casual dinner. Carolina Herrera has several stunning looks to pick from in silk faille, silk taffeta, and chiffon. She emphasizes the waist by way of grosgrain bows and other embellishments. Vera Wang also works with embroidery, producing beautiful garments with a nod toward an ethnic theme that can be amped up for evening or played down for day.

Chanel’s luxurious offerings from its cruise collection are described by its designer, Karl Lagerfeld, as “a mixture of sophistication and sport, with a play on proportion.” Ranging from denim to chiffon to the house’s famous tweed emblazoned with the double “c” logo, the collection gives travelers a Parisian flair. Mix a sparkly black tweed waistcoat with a swimsuit, t-shirt, or chiffon blouse. Chanel Cruise also offers several versions of the versatile “little black dress” in viscose rayon, asymmetrical satin gowns, sequined skirts, pleated culottes, vertical striped tube dresses, and straight-legged jeans accented with tweed.

With so many options, it’s possible to dress appropriately and look chic on any cruise – even if you pack the night before.