We were sitting on the Tahitian Princess fantail, eating fresh pineapple and admiring Bora Bora’s majestic Mount Otemanu, when a Detroit couple, Ray and Lois Tylenda, invited us to share a car rental and tour the island. Doug and I didn’t know the Tylendas very well, but we had taken several Princess shore excursions during our Polynesian cruise and were ready for a change. We agreed to go.

An orange-and-white tender boat dropped the four of us ashore in Vaitape, a tropical settlement with metal-roof island houses and a lively covered market. At Fare-Pitt Rent-A-Car, we slapped $100 on the counter and took the keys. With Ray behind the wheel, we headed off along the coastal ring road, figuring we could hardly get lost. We stopped at coral-sand beaches, climbed giant boulders, and browsed for black pearls in gift shops. We snapped pictures outside Bloody Mary’s bar, a favorite watering hole for the rich and famous. It was a glorious adventure. We returned to Vaitape elated, and a bit smug, that we had seen and done things at our own pace — something not possible on a bus tour. And we had saved a wad of dough.

The question of whether to book a sightseeing excursion through the cruise line or to wing it alone onshore can leave some passengers in a quandary. There’s no simple answer.

“I love going solo and walking around the ports, stopping in Internet cafes, and sampling street food,” said Anne Preston of Ann Arbor, Mich. “I might miss some big things on my own, but I get immersed in the local culture.” During her 12-day sailing from Buenos Aires to Rio de Janeiro aboard the Oceania last December, however, Preston booked an excursion to Sao Paulo. “We drove inland from the port for two hours to reach Sao Paulo, and I couldn’t have done that myself,” she said. “Still, it’s good to do a combination of both types of sightseeing.”

In the past, whenever John and Jana Hanson set sail on vacation, they had one rule: no group tours. “We never liked shore excursions because we always ended up on a bus with 50 people,” said the Grand Rapids, Mich., couple. They had a change of heart, however, when they took a 12-day northern European voyage on Holland America’s Eurodam in May. The ship’s itinerary included St. Petersburg, Stockholm, Helsinki, Copenhagen, and other magnificent Baltic Sea cities steeped in history and culture. The Hansons signed up for a shore excursion at every port.

“Our excursions cost almost as much as the cruise, but we wouldn’t have done it any other way,” John said. “It was fabulous touring these wonderful old cities and seeing their highlights. Knowledgeable guides gave us a real lesson in history.”

In Tallinn, Estonia — a European Capital of Culture for 2011 — the two retirees left their tour group early and lingered a few hours longer in the Old Town. “We wandered around Viru Square, had lunch in a French-style cafe, and then walked one mile back to the ship,” John recounted. “We managed to get by, speaking limited English.” In St. Petersburg, however, the Hansons didn’t stray far from their shipmates while visiting the Hermitage and Catherine Palace because the ship’s blanket visa only covered organized tour groups.

Cruise lines are doing more these days to help passengers enrich their onshore experiences. “We are watching the trends, listening to our guests, and offering a wide variety of options to suit all tastes,” said Erik Elvejord, Holland America’s director of public relations. Passengers can go sightseeing by bicycle, combine excursions with culinary lessons, and take behind-the-scenes tours of museums, led by multilingual guides. The line also will arrange private cars, vans, boats, and planes, with or without guides, to help guests customize their tours, according to Elvejord.

There are certainly advantages to letting someone else do all the heavy lifting while you lean back and enjoy the sights. Tour groups often receive red-carpet treatment not accorded to lone travelers. In St. Petersburg, the final port on a weeklong river cruise from Moscow, Doug and I took a group tour to the splendid Peterhof Palace and gardens. To our surprise, our guide marched boldly past several hundred tourists waiting in line and led us to the palace entrance, where we were immediately admitted. While sailing the Yangtze River shortly before the dam was completed, our contingent from the MV Victoria were treated like visiting dignitaries and entertained by Chinese schoolchildren. On last year’s Ocean Princess cruise through Southeast Asia, two passengers became separated from our tour group at the Grand Palace in Bangkok. A local guide returned to the palace grounds and searched until she found the strays.

Unexpected weather events and mechanical meltdowns can unravel onshore travel plans. An advantage of booking a shore excursion is that the ship will wait for guests to return to the vessel. That’s not the case for passengers who arrange independent sightseeing jaunts with a private taxi or tour operator. We experienced this peace-of-mind perk in Puerto Madryn, Argentina, during a Cape Horn cruise aboard the Celebrity Infinity. Our tour bus was caught in a horrific dust storm while returning from the Punta Tombo Penguin Wildlife Reserve. To accommodate our delay, the ship remained in port well past its scheduled departure time.

Passenger safety is always a concern. “We know our operators are fully bonded and will show up,” said Elvejord. However, no cruise company can completely guarantee the safety of its tour groups. In February, 22 Carnival cruise passengers were robbed during a guided nature trail excursion in Puerto Vallarta, Mexico. Nevertheless, individuals traveling alone still tend to be easier targets for criminals or rogue taxi drivers. It’s all about safety in numbers.

Despite the pluses, cruise sightseeing tours can be overly regimented and pricey. Average costs range from $40 to $350 per person. Private car, motor-scooter, and bicycle rentals offer attractive, lower-cost alternatives to prearranged tours booked through the ship. Hiring a local taxi with an English-speaking driver who agrees to set a firm price, or chipping in with other passengers to pay for a privately run minivan tour are also options.

Paul and Evelyn Kaplan, a South African couple sailing on our Southeast Asia voyage, pushed the boundaries of self-styled touring during a stop on Thailand’s Ko Samui island. They hired a motor scooter in Na Thon for 200 baht ($7) and went around the island. “We stopped at convenience stores to fill up the gas tank with a Coke bottle of gasoline,” said Paul, who had never driven a scooter before.

Public transportation is often cheap and readily available at major ports. In Hamilton, Bermuda, we used the local ferry to cruise to outlying islands. In Hong Kong, we rumbled around the island atop the double-decker Big Bus and then zipped up to Kowloon’s flower market on the ultramodern MRT subway.  

Some of our most memorable travel expeditions have been on foot. After viewing the changing of the guard at Taiwan’s Chiang Kai Shek Memorial Hall, we whiled away the evening in Keelung’s Miaokou night market near the seaport terminal. The exotic sights, sounds, and smells emanating from stalls, where women stirred pots of pig’s-blood soup, deep-fried strange insects, and sold octopus-on-a-skewer, remain as vivid today as they were then.