The 62-passenger Crystal Esprit, the new “yacht” from Crystal Cruises, has a retractable marina that comes out not just on sea days, but most afternoons when the ship is in the quiet harbors of the Seychelles islands or in the quietest ports of the Mediterranean. Sign up for dives, waterskiing, wakeboarding, snorkeling, or kayaking, as well as a chance to use the ship’s jet skis. You can also take a dip in the small pool located in the water sports platform itself, or go fishing off the side. 

Make a Splash: It’s hard to top the ship’s three-person submarine, which (for $595 per person) you can spend 30 minutes exploring the bottom of the Indian Ocean, looking for schools of parrot fish, trumpet fish, tiny lemon sharks, and even sea turtles. 

This 450-passenger luxury ship has its own water sports marina that the staff opens up in warm-weather harbors. You can borrow complimentary equipment — such as kayaks, banana boats, and pedal boats — and jump right off the platform into the sea for a swim, or sign up for waterskiing. Sure, Seabourn Sojourn and Seabourn Quest (Odyssey’s sister ships) have the same platform, but they do world cruises so they get less use out of it than Odyssey, which sails the Mediterranean all summer long and the Caribbean in wintertime. 

Make a Splash: While in the Caribbean, the ship offers a “Caviar in the Surf” party, where Champagne and caviar are served off of surfboards. Spend the afternoon sipping Moët or Veuve and smearing domestic caviar on blini while you wait for your turn to water-ski. 

All the Windstar sailing and motor yachts have retractable water sports platforms, but this 148-passenger yacht’s water toys get the most use because the ship cruises year-round in the calm waters of French Polynesia. You can borrow complimentary equipment for a wide variety of water sports, including snorkeling, waterskiing, wakeboarding, sailing, windsurfing, paddleboarding, and kayaking.

Make a Splash: The ship has a giant inflatable water trampoline that is sure to make you feel like a kid again.

Doing the Med in summer and Caribbean in winter, the 112-passenger SeaDream I and SeaDream II each have retractable marinas packed with toys, including Laser sailboats, a banana boat, water skis, snorkeling equipment, kayaks, and stand-up paddleboards. You can also dive right off the marina into the sea, which not all lines allow. 

Make a Splash: If you have a need for speed, SeaDream I and SeaDream II both come stocked with a pair of wave runners, so you can challenge your partner to a friendly race around the ship.

On this five-masted, fully rigged 227-passenger sailing ship, the water sports program includes scuba and snorkeling, plus complimentary Sunfish sailing, waterskiing, and banana boat rides, launched from the built-in marina.

Make a Splash: Did you master your Sunfish with confidence? Test those newfound skills by offering to help the captain sail the ship itself when he calls for volunteers. 

On this posh 332-passenger ship, which sails from Tahiti year-round, you can snorkel or dive in coral gardens where you might spot brightly colored tropical fish, stingrays, and even small reef sharks. From the retractable marina you can borrow complimentary equipment including windsurfers, paddleboards, and kayaks. Always wanted to learn how to dive? Those who want to try can get PADI certified while onboard, for a fee. 

Make a Splash: You can also take advantage of the water sports marina on Paul Gauguin’s motu, a small private island, where you’ll be the only ones in the surf. 

This 5,400-passenger Royal Caribbean ship may not have a marina, but it still has extensive onboard water sports programs. Scuba instruction is available from PADI SeaTrek Dive instructors, who teach classes for both beginners and those who need a refresher course in the ship’s sports pool, where you can also play water polo or swim laps (a rarity at sea).

Make a Splash: Have a hankering to hang 10? You can learn to surf on the ship’s two FlowRider simulators, where an instructor guides you until you are ready to ride the waves on your own. The simulator is complimentary, or you can pay for longer lessons.