While both are Oasis-class sisters, the primary differences in 2026 stem from their respective "Royal Amplification" schedules. Oasis of the Seas was modernized in 2019, receiving the Ultimate Abyss slide and the Perfect Storm waterslides earlier than its sister. Allure of the Seas, however, underwent a massive $100 million "amplification" in early 2025. This 2025 refit added the Pesky Parrot tiki bar and the Mason Jar Southern Restaurant, features not found on Oasis. Allure also technically holds the title of being 50 millimeters (2 inches) longer than Oasis due to slight variations during construction in Finland. While the layout of the seven "neighborhoods" remains identical, Allure now features more updated youth spaces (Adventure Ocean) and a more modern Solarium design following its recent dry dock.