Choosing a Royal Caribbean cruise is really two very different decisions in one. The line operates everything from floating megaresorts carrying over 5,600 passengers to modest ships holding barely 2,000 — and which end of that scale you book will shape your whole holiday.

At the top sit the three Icon-class ships: Icon of the Seas (2024), Star of the Seas (2025) and the new Legend of the Seas (2026), each measuring 248,663 gross tons and tied as the largest cruise ships ever built by any line. Legend of the Seas can carry up to 7,600 passengers at maximum occupancy, a record. These vessels pack in more bars, restaurants, theatres and top-deck attractions than anything else at sea, including a family-focused outdoor area called Surfside aimed at parents with young children. Icon is also expanding: Hero of the Seas arrives in August 2027, with three more unnamed sister ships following in 2028, 2029 and 2030.

Just below the Icon class come the Oasis-class giants — Utopia, Wonder, Symphony, Harmony, Oasis and Allure of the Seas — all between roughly 225,000 and 236,000 tons. On these you get three separate pool areas, surfing simulators, mini-golf, a zip line, ice rinks, big casinos and Broadway-style shows. A seventh Oasis-class ship is due in 2028, sized like Utopia.

At the other end of the list, the smallest ship in the fleet is Grandeur of the Seas: 73,817 tons, built in 1996, and about one-third the size of an Icon-class vessel. Aside from a climbing wall, its top deck sticks to pools, whirlpools and sun decks — the 1990s way. It has a loyal fanbase nonetheless, and its lower daily price is part of the appeal. The Vision-class quartet (Enchantment, Rhapsody, Vision and Grandeur) all carry around 2,000 passengers.

Why does the size split matter? Because bigger means more to do but more crowds, while the small ships trade waterslides and surf simulators for a calmer onboard vibe and access to ports that giant vessels physically cannot enter. That second point is set to matter more: Royal Caribbean's new Discovery class, debuting in 2029 with a second ship in 2032, is specifically designed for smaller ports and is expected to replace the oldest, smallest ships in the fleet.

The practical takeaway: if you want the theme-park-at-sea experience, aim for Icon or Oasis class. If you'd rather avoid queues and hordes, look at the Radiance or Vision class — you'll pay less per day and wake up in ports the giants skip. Either way, check the ship's class before booking, not just the price.