Available On: Voyager-, Freedom-, Quantum- and Oasis-class ships

These Royal Caribbean ships offer the rare opportunity to get PADI certified or re-certified at sea. If you've always been curious about diving but haven't yet taken the plunge, there's a 30-minute “Try Dive” introductory course in a ship pool, as well as Discover Scuba, which includes instruction and a dive from a beach.

Cost: Try Dive: $29 per person; Discover Scuba: $119 per person

Available On: Freedom-class and Oasis-class ships

A dozen Royal Caribbean ships are equipped with FlowRider simulated surfing pools (Oasis-class ships have two!) so you can get on a board and challenge the waves. Sure, you can wait in line and try the machines for free but these one-hour private lessons, which typically group together six to eight passengers, give you a serious leg up.

Cost: $69 per person

Available On: Oasis- and Quantum-class ships

The Vitality Spas on the Royal Caribbean ships have lots of state-of-the-art equipment you can use for free, but when you get bored with that spring for a fitness class. The best of the options: a high-energy spinning classes, held in a sleek FlyWheel studio.

Cost: $25 per class

Available On: Oasis- and Quantum-class ships

Royal Caribbean has made much of its updated onboard Internet access with speeds that match broadband on shore, and Voom is indeed really great shipboard Wi-Fi. They have a basic Surf package, designed for those who just want to check email and post photos on sites such as Instagram, but you should choose the Surf + Stream package, which is strong enough to watch videos and listen to music. Best of all, if you miss your favorite TV shows, Voom is powerful enough to let you stream them online.

Cost: Packages start at $12.99 per day for Surf and $17.99 for Surf + Stream for your first device. (You’ll pay less for each device added after that). Note: For these prices you have to pay for every day of your cruise. If you want just a single-day pass it's $19.99 for Surf or $27.99 for Surf + Stream.

Available On: Freedom-, Radiance-, and Voyager-class ships

This three-hour experience combines comedy and dining as you join a small group of fellow passengers in solving a “crime.” Best of all, you’ll meet a lot of fellow passengers.

Cost: $65 per person, including a four-course dinner with wine at the Giovanni's Table Italian restaurant