And yes, thongs can be common around the pool deck. We've also searched the websites of all the major cruise lines, including Carnival, Norwegian, Royal Caribbean, and Princess Cruise Lines. Nowhere did we find any sort of language from the cruise lines mentioning thong swimsuits or restrictions against them.

Royal Caribbean's official dress code for 2026 emphasizes a "Casual" atmosphere for the pool deck, but it includes a "high-fidelity" requirement for decorum and family-friendliness. While there is no explicit ban on thong bikinis in the written policy, the guidelines state that "bathing attire" is restricted to the pool and sports decks and that "appropriate footwear and cover-ups" are required when moving through the ship's indoor areas. In practice, many travelers report that thong-style bottoms are common in adult-only areas like the Solarium. However, in main pool areas where families with children are present, wearing a very revealing thong may lead to "high-fidelity" discomfort or a polite request from crew members to use a sarong or cover-up. The general rule for a 2026 cruise is that while fashion is personal, the ship is a shared public space with many cultures and age groups; keeping the most revealing swimwear for the tanning decks or private "Perfect Day" beaches is considered best practice for maintaining a respectful environment for all guests.