Carnival just launched a shoe-recycling program with Miami recycler Sneaker Impact: unclaimed shoes left in cabins get sorted by condition — wearable pairs are resold to small businesses abroad, worn-out ones are broken down into athletic surfaces and yoga mats. In its first month, five ships alone kept 500+ pairs out of landfills, with fleet-wide potential near 50,000 a year. You can now donate a pair you outgrow mid-trip, too.

That $399 headline fare is usually about half of what you'll actually spend. We break base fares down by line, then stack on gratuities, drinks, Wi-Fi, and excursions — the rule of thumb is to budget 60–80% on top of the base fare for a mainstream 7-night sailing. Know the real number before the disembarkation-morning statement surprises you.

Royal Caribbean's Icon of the Seas takes the crown — its six-slide Category 6 park includes Frightening Bolt, billed as the tallest drop slide at sea. We rank the top slide ships across MSC, Norwegian, and Carnival, and flag the height rules worth checking before you book. Best part: every one of them rides free.