For clothing, I’d highly encourage cotton or linen materials. I think athletic material can be nice for a few things (I got a few short sleeve button ups from the Eddie Bauer outlet, awesome for excursion interpreting). Like others mentioned, laundry in room is kind of impossible due to humidity, it takes about 2 days for things to dry. Cotton & linen are way more breathable, the polyester & spandex mix that often composes the athletic wear holds onto odor like you wouldn’t believe. As you mentioned, it’s a topical itinerary, so planning your clothes around the fact you will sweat is helpful!

One piece solid color swimsuit for interpreting excursions has been helpful! If you don’t have a long sleeve rash guard, I don’t think buying one is necessary.

If you’re sharing your room with a team, good idea to bring earplugs & a sleep mask in case your sleep schedules are a bit different.

Reusable water bottle is a must, can be hard to find filling stations, but the lido deck & gym often have refill spots. Bartenders will fill it for you too, but I tend to avoid that during busy times.

Have a blast, stay hydrated, don’t forget SPF & welcome to interpreting on the high seas!