The rhythmic, rocking motion of floating on water instantly relaxes you, making it the perfect way to spend your vacation. So whether you’re a cruiser, a fisher, a kayaker or a tourist who wants a fresh angle on a big city, a boat is the way to go.

Puerto Rico: Laguna Grande

The celestial glint seen in Puerto Rico’s night sky has a distinct rival in the waters of Laguna Grande. Located about an hour and 20 minutes from San Juan, the lagoon, otherwise known as Bio Bay, lays claim to countless tiny organisms that glow in the dark like some sort of underwater star field.

Pure Adventure husband-and-wife co-founders Carlos Castro and Yolanda Ramos both hold degrees in marine biology. A staff marine biologist leads a two-hour evening kayak tour of the lagoon and its bioluminescent phenomena. According to Castro and Ramos, only four bioluminescent bays and one lagoon exist on the planet.

Veiled by mangrove trees, Laguna Grande sits in a natural reserve on the northeast tip of Puerto Rico and basically remains untouched, allowing the microorganisms to proliferate. Keep an eye out for other lagoon residents such as robalo fish, heron and pelicans.

Guests not only glide in a kayak through this otherworldly experience, but get a science and history lesson courtesy of their guide. Tours take place twice each operating day from the launch site in the small fishing community of Las Croabas. Organizers suggest the tour is for those age 6 and older. Kayakers who work up an appetite after paddling can rest easy. Your guide can recommend a nearby eatery.

5:30 and 7:15 p.m. Mondays-Saturdays. Call or check website as schedule changes periodically. $51.36 per person. Parque de la Juventud, Street 987, Km. 5, Las Croabas, Fajardo, Puerto Rico. 787-202-6551, www.pureadventurepr.com.

Mississippi: riverboat casinos

The tradition of riverboat gambling didn’t necessarily sail away into the history books. It can still be found, including in two different parts of Mississippi.

Although permanently docked to the shore, a riverboat houses the Isle of Capri Casino in Natchez, offering a choice view of the Mississippi River. The casino’s hotel, perched on top of a hill by the river, offers shuttle service to and from the 24-hour casino.

Inside the boat, guests have access to three levels of gambling. The flashing bulbs of more than 600 slot machines help brighten the activity. Dealers preside over gaming tables, including blackjack, craps and three-card poker. Casinos and buffets go together like coins and slots, and this one resides on the riverboat’s upper level. Although homestyle grub has prominence, an evening seafood buffet takes over on Fridays, Saturdays and Sundays.

Isle of Capri Casino, 53 Silver St., Natchez, Miss. 601-445-0605, http://natchez.isleofcapricasinos.com.

Another riverboat-themed casino sits along the Mississippi River in Vicksburg. Ameristar Casino Hotel Vicksburg also has an adjacent hotel and keeps all of its gaming action in the boat itself.

The docked watercraft buzzes to life with about 70,000 square feet of gaming. More than 1,500 slot and video machines entertain guests. Those looking for a more analog gambling experience partake in one of 27 table games or belly up to one of the 10 tables found in the live poker room.

Ameristar Casino Hotel Vicksburg, 4116 Washington St., Vicksburg, Miss. 601-638-1000, www.ameristar.com.

Orange Beach, Ala.: fishing charters

Deep sea fishing may sound like an excursion best suited for a gaggle of guys. Tell that to Tom Ard, owner of Fairwater II Charters, and he’ll say you’re way off course. About 85 percent of the chartered fishing trips his company handles involve families.

Ard said he makes the experience suitable for the 6-year-old newbie as well as the avid fisherman. That means the speed of the boat, the type of fishing tackle, and the size of the rods and reels stay accessible to a wide range of people.

The trip into the Gulf of Mexico launches out of Zeke’s Marina in Orange Beach. An average fishing excursion takes guests 12 to 15 miles out to sea. The boat’s deck hand assists those fishing, helping them snag red snapper, triggerfish, amberjack, grouper and more.

Guests must bring their own lunch, but the crew happily will grill hamburgers, hot dogs, ribs, chicken and so on. Ard said he specializes in entertaining. So when guests aren’t fishing, they can kick back in a heated and air conditioned cabin complete with 37-inch TV and bathroom. Trips take place any day, weather permitting. Ard said most customers opt for the six-hour jaunt.

Daily. Zeke’s Landing Marina, 26619 Perdido Beach Blvd., Orange Beach, Ala. 251-979-2682, www.fairwaterfishing.com/faiwaterII.html.

Bahamas, eastern and western Caribbean: cruise

An island-hopping spring-break escape can be just a cruise away.

Disney Cruise Line offers several options aboard each of four ships. The recently updated flagship Magic and its counterpart Wonder hold up to 2,713 guests, while the larger Dream and Fantasy ships fit as many as 4,000 cruisers. Each is equipped with amenities ranging from multiple pools and theme park-ready water slides to movie theaters screening first-run, Disney-owned films. Nightly Disney-themed musical stage productions offer Broadway-style entertainment.

The cruise tradition of copious edibles holds true, with lunch and breakfast buffets, grab-and-go bites at several spots, complimentary room service, and dinner in one of three themed main restaurants.

Although Disney characters pop up for photo ops throughout the ship, it’s a misconception that Disney cruises are just for broods with tiny travelers. All of the ships have adults-only nightclubs and bars for dancing, entertainment and drinks. A separate pool area for grown ups stays serene. Elders slip away to the full-service spa and adults-only pay restaurants, like the uber swanky Remy on the Dream and Fantasy. Kids, from toddlers to teens, have their own respective supervised play areas.

All ages should appreciate Castaway Cay, Disney’s own private island in the Bahamas with its glass-like waters and bevy of excursions ranging from snorkeling to parasailing to stingray experiences. And even the most jaded adult can’t help but gaze at the fireworks display, which takes place on each cruise.

Trip options in March and April include three- and four-night Bahama cruises on the Dream and Magic out of Port Canaveral; seven-night western and eastern Caribbean cruises on the Fantasy out of Port Canaveral; and five-night western Caribbean cruises on the Wonder out of Miami.

1-800-951-3532, http://disneycruise.disney.go.com.

New York City: Staten Island Ferry

The Big Apple can put a bit of wear and tear on the wallet, but this boat ride is gratis.

The ferry’s main purpose is transporting Staten Islanders to and from Manhattan around the clock. Hop on at either the St. George Ferry Terminal in Staten Island or the Whitehall Ferry Terminal in Manhattan.

Tourists take advantage of the five-mile, 25-minute cruise with its scenic view of New York Harbor. Tip back a beer or munch on snacks from the concession stand, but make sure and have a camera within reach. The watercraft floats past the Statue of Liberty and Ellis Island, as well as the cloud-touching towers and sweeping bridges of Lower Manhattan.

Although the ferry no longer allows motorized vehicles on board, you can ride with a bicycle in tow. Guests aren’t allowed to stay on the boat for round trips. Everyone has to re-board through the waiting room at each port. The schedule varies, so check online for more details.

Weekend travelers can take advantage of the 75 trips taking place each Saturday and the 68 sailings on Sundays. There are periodic special events, including the annual Tango on the Ferry dance in July.

24 hours daily. Free. Whitehall Terminal Manhattan, 4 South St., New York; St. George Terminal Staten Island, 1 Bay St., Staten Island, N.Y. www.siferry.com.

Miami: airboat tours

“Enjoy nature’s river of grass,” reads the hand-painted wooden sign with the gargantuan Indian arrow pointing the way to Buffalo Tigers Florida Everglades Airboat Tours.

Located on the Miccosukee Indian Reservation, this tour begins beneath a thatched roof docking area as visitors board the airboat, a flat-bottomed vessel powered by an aircraft-style propeller.

There are plenty of thrills throughout the 45-minute adventure as the guide zips the airboat through the swamp and sawgrass. Like a sort of real-world nature documentary, the guides dish informative nuggets on the Everglades and its wildlife.

And when it comes to alligators, your host knows just where to look, and he’ll steer the boat extra close to the long-jawed inhabitants. You might see creatures of all sizes or even a nest of alligator eggs. Don’t be surprised if the guide gets up-close and personal with a gator.

The boat stops at an island for a look at a traditional Indian camp. Raccoons will come out to greet you, and prove to be friendly with human guests.

9 a.m.-5 p.m. daily. $27.50; $13.75 ages 6-10; free ages 5 and younger. 29701 S.W. 8th St., Miami. 305-559-5250, www.buffalotigersflevergladesairboattours.com.

Bryson City, N.C.: river kayaking

Located just off the banks of the Nantahala River in western North Carolina, Endless River Adventures caters to kayakers, both seasoned and wet behind the ears.

The staff bases its kayak experiences on the private instruction model by putting together groups of one to four students, each with similar skills. Its small-group philosophy gives guests the feeling they’re being tutored by a personal trainer. Whitewater kayaking lessons are more skill-centered.

The day begins on the lake with a rundown of the basics. Later in the afternoon, the instructor takes paddlers to an easier whitewater section of the river. They’ll practice their newfound skills by hitting a short river run. The first day for a beginner may prove frustrating, so it’s suggested that you go at it for two days.

Daylong kayak instruction typically costs $230 for one person, $350 for two people, $390 for three and $440 for four. Paddlers who provide a vehicle large enough to haul the boats and the trainer receive a $30 discount.

For flat-water kayaking, a sunset or morning tour includes two hours of paddling on the lake. Co-owner Ken Kastorff suggests bringing your camera. The guide makes sure paddlers see eye-widening sights like a bald eagle or other local wildlife. These flat-water excursions cost $45 per person.

Endless River Adventures also offers outdoor experiences that require less instruction. Visitors can whitewater raft on the Nantahala and Ocoee Rivers, or cast off with some fly fishing.

Spring break vacationers can take advantage of an upcoming seasonal special. Endless River Adventures is partnering with a pair of area lodges, offering discounts on activities and accommodations. Those who get bitten by the kayaking bug may want to look into the company’s kayak excursions in Ecuador, where they maintain a lodge located in a cloud forest in the Amazon.

9 a.m.-5 p.m. daily. 14157 Highway 19 West, Bryson City, N.C. 1-800-224-7238, www.endlessriveradventures.com.