clothes while youre losing weight.

Second-hand shops/thrift stores can be a great place to source a temporary wardrobe. Depending on the duration of the trip and available amenities (laundry services/washing machines), perhaps only a minimal wardrobe is necessary? I can imagine wearing the same pants/shorts multiple days and just changing shirts/tops daily, for example.

When is your cruise? If it's a couple of months off, how much different do you think your body will look? Don't just consider your weight, but how your body has already changed. I'm 5'2" tall, and have worn the same size clothes even after losing 20 pounds. It all depends on where you lose weight.

Cruises are casual, and many cruise lines don't require the formal clothes for the captain's dinner. DH & I have been on 3 cruises. The last cruise we went on, we didn't bring any fancy clothes and skipped the formal dinner. There were so many other dining options, we didn't miss going to it.

If you do need to buy new clothes, opt for separates, even if you get them in different sizes. I did laundry on the ship, so that we didn't have to bring outfits for every day. I mixed and matched tops and bottoms. A single pair of jeans can go with just about anything. A pair of simple black pants can pair with a fancy top if you want to dress up, and can be worn multiple times. Elastic waist and/or knit pants work well while losing weight.

The reality of cruising is that most people don't look anything like what you see in the brochures and commercials - they're professional models. Instead, cruise passengers look just like the people you see everyday, some dress up, some are completely casual. Some look like models, most don't.

Remember, you're dressing for yourself, not to impress other people, so find what's comfortable and what you like, and what you can wear after the cruise. (I once bought a fancy jacket for a cruise, wore it for a couple of hours, had my picture taken, and never wore that jacket again.) That was money I just threw away.

I think it's always helpful to have a couple outfits that fit you well at your current weight. Shopping thrift stores can be a great way to save money, but if you're not someone who enjoys shopping (I don't particularly) or are looking for something specific, then online shopping can be great. I always check the return policy before I buy anything, and look at both the sizing chart and reviews to get a better idea of what size should fit. I've also built a much higher appreciation for things with a drawstring in addition to an elastic waist and that have some spandex content, so I can typically wear them through a longer weight range.

I sew. For dress up I made a simple poncho of shiny blackish metallic fabric that went over anything. Also a fancy scarf could work. Practice several ways to tie.
Wait until fairly close to time. I've been bottom heavy all my life. But surprise! Last time I lost 1 blouse size and 10 pants sizes! You don't know what's going to happen until it happens!
Have a fun trip!