The most impressive sights in the Cayman Islands are on and under water, and several submarines, semisubmersibles, glass-bottom boats, and Jules Verne–like contraptions allow you to see these underwater wonders without getting your feet wet. Sunset sails, dinner cruises, and other theme (dance, booze, pirate) cruises are available from $30–$90 per person.
Atlantis Submarines. This submarine takes 48 passengers safely and comfortably along the Cayman Wall down to 100 feet. Peep through panoramic portholes as good-natured guides keep up a humorous but informative patter. A guide dons scuba gear to feed fish, who form a whirling frenzy of color rivaling anything by Picasso. At night, the 10,000-watt lights show the kaleidoscopic underwater colors and nocturnal stealth predators more brilliantly than during the day. Try to sit toward the front so you can watch the pilot's nimble maneuverings and the depth gauge. If that literally in-depth tour seems daunting, get up close and personal on the Seaworld Observatory semisubmersible (glorified glass-bottom boat), which just cruises the harbor (including glimpses of the Cali and Balboa shipwrecks). The cost is $89–$104 (children $49–$64) for the submarine, $39 (children $24) for the semisubmersible. There are frequent online booking discounts. 30 S. Church St., George Town, Grand Cayman, KY1-1003. 345/949–7700; 800/887–8571; www.caymanislandssubmarines.com.
Jolly Roger. This is a two-thirds-size replica of Christopher Columbus's 17th-century Spanish galleon Niña. (The company also owns the Anne Bonny, a wooden Norwegian brig built in 1934 that holds more than 100 passengers.) On the afternoon snorkel cruise, play Captain Jack Sparrow while experiencing swashbuckling pirate antics, including a trial, sword fight, and walking the plank; kids can fire the cannon, help hoist the main sail, and scrub the decks (they will love it even if they loathe doing chores at home). Evening options (sunset and dinner sails) are more standard booze cruises, less appropriate for the kiddies. Food is more appropriate to the brig, and it's more yo-ho-hokum than remotely authentic, but it's fun. Prices are $25–$65 (children's discounts available). South Terminal, next to Atlantis Submarines, George Town, Grand Cayman, KY1-1003. 345/945–7245; www.jollyrogercayman.com, www.piratesofthecaymans.com.
Nautilus. On this semisubmersible you can sit above deck or venture below, where you can view the reefs and marine life through a sturdy glass hull. A one-hour undersea tour is $50. Watch divers feed the fish, or take the Captain's Nemo's Tour that includes snorkeling; a catamaran cruise to Stingray City and land-sea tours are also offered. As on the Atlantis semisubmersible, you get a close-up look at the Cheeseburger Reef and two of Cayman's mysterious shipwrecks (Cali and Balboa), with a bit of entertaining educational narrative. 93 N. Church St., George Town, Grand Cayman. 345/945–1355; www.nautilus.ky, www.nautiluscayman.com.
Sea Trek. Helmet diving lets you walk and breathe 26 feet underwater for an hour—without getting your hair wet. No training or even swimming ability is required (ages eight and up), and you can wear glasses. Guides give a thorough safety briefing, and a sophisticated system of compressors and cylinders provides triple the amount of air necessary for normal breathing while a safety diver program ensures four levels of backup. The result at near-zero gravity resembles an exhilarating moonwalk ($89, $99 for Ultimate Stingray City excursion). Cayman Cabana, 53 N. Church St., George Town, Grand Cayman, KY1-1109. 345/949–0008; www.seatrekcayman.com, www.snubacayman.com.