Our small boat bobbed in the clear blue waters of the Aegean Sea, anchored near a rocky uninhabited spit of land. In the distance, the white cityscape of Fira, Santorini, glistened against high seaside cliffs. I shimmied down the ladder into the sapphire sea. A few minutes later, my party of 10 was swimming toward an otherworldly lagoon. Its dark yellow color, sulfuric scent and hot springs were the products of volcanic activity below. In the shallows, we wiped the iron-rich mud on our faces.

All part of our mega-cruise ship adventure. Sort of.

While most of our fellow passengers of the Celebrity Constellation were sitting at cafes or shopping on Santorini — where the ship had docked — my wife and I took a different approach to a shore excursion. We joined only four other couples on a private boat tour to explore the more off-the-beaten path spots.

A few years ago my images of large cruise ships were of buffet lines, regimented schedules and herd mentality. I was, frankly, uninterested.

No more. I’ve learned that cruises can afford singular adventures, away from the crowds. It is even possible to style a mega-liner cruise to fit almost any image you might have of a dream vacation. It just takes a little more work, in the form of pre-cruise research.

My wife, Margie, and I returned this summer from our third Mediterranean cruise, all on ships of about 3,000 people. We have gained experience from each trip, and perhaps our most important piece of knowledge is this: There is a wealth of wonderful onshore experiences beyond the excursions offered by the cruise line.

Ship offerings can be expensive, and many require you to board a bus and, upon reaching the destination, follow a sign-carrying tour guide.

Some ship tours are just fine, maybe even advisable for first-time visitors to a foreign place. We were much more inclined to take ship tours on our initial Mediterranean trip, and we have no regrets over spending an afternoon in Pompeii, or touring the ancient city of Ephesus, or even taking a rather lengthy bus trip to Florence on cruise excursions. Having never previously visited any of those spots, we soaked up the information provided by the guides. In Athens, we relished the Acropolis tour leader who pointed to lemon trees as we drove by, saying they were lousy in taste, but just fine for throwing at local police and politicians.

Nonetheless, our most memorable experiences have come when we either ventured off on our own, or happened upon a private tour, sometimes by planning, sometimes by chance.

Seek a top-notch itinerary

How did we wind up swimming in hot springs off a volcanic island during the cruise ship stop at Santorini? It was mostly serendipity — and my wife’s adventurous nature.

On the train ride from Rome, where we’d landed, to Citavechii, the ship’s departure port, we rode with a couple named Tom and Sherry from Orlando. After the cruise got underway, we met an English farming couple, David and Fiona, who told us that Tom and Sherry were looking for two more people to fill out a 10-person small-boat tour in Santorini. The precise nature of how those two couples met escapes me, but those sorts of unexpected encounters happen with more regularity than one might expect. We sent word that we’d love to take those two spots.

Santorini itself is a jewel of the Greek islands, with whitewashed homes entrenched into seaside cliffs. Add swimming and you’re talking dream vacation.

I’d venture that most of the ship’s passengers spent their day in either Fira or neighboring Oia, jostling with hundreds of tourists from the several cruise ships that dotted the port. For those who love shopping — the standard fare being jewelry, clothing or trinkets — six hours in Fira, with a coffee or wine break, can be lovely. But way too predictable.

I might have enjoyed strolling those narrow streets, but my wife, the true adventurer, prodded us to sign up for Tom and Nancy’s tour. Happily, I now realize that there are better ways to spend a day in Santorini than shopping and sipping coffee.

While the vast majority of our ship’s passengers were deciding which one of three ways to get to the top of Fira — the choices being donkey ride, walking the same donkey path while dodging the inevitable donkey droppings, or cable car — we were picked up by a small Greek fishing boat run by Capt. Stathis of Amenos sea trips and dropped at a tiny harbor on Santorini. Included in the price of $80 per couple was a bus to take us round-trip to Oia, at the top of the island. for two hours of on-our-own shore time. Time enough for trinkets and coffee!

When we returned to the harbor, Capt. Stathis took us for our swim and then to a tiny church on the other side of the island.

When we reflect on this summer’s cruise, both Margie and I immediately agreed that the stop in Santorini was our favorite, with Naples as No. 2. And the choices weren’t obvious, because our ship stopped at three other Greek islands — Mykenos, Crete and Rhodes — plus Malta, Athens and Kusadasi, Turkey, before we disembarked in Venice.

We took the Celebrity Constellation June cruise because of the itinerary, which I can’t stress strongly enough is the best method for selecting a cruise.

An Amalfi Coast beach

What made Naples rival Santorini for memories? Another private tour, this one found by my wife on the website Cruisecritic, a tremendous resource for information about cruise ships and excursions, both private and ship offerings.

This tour was organized by a delightful Florida retiree named Nancy, whose sardonic personality found a soul mate in the eight-passenger van’s driver and guide, Anthony. The van took us down the windy, steep cliffs of the Amalfi Coast, the scenery and vertical drops leaving all of us breathless.

All except Anthony, who hardly seemed to notice, which I think — although I am not certain — was a good thing. At one point, Anthony started singing the song “Volare.” Between singing, he and Nancy bantered, with the rest of us occasionally sneaking in a one-liner. Mostly I remember laughing.

The trip ended in the postcard-beautiful town of Positano, where we had 90 minutes on our own. My wife and I headed to a beach favored by locals, buying a bargain beach towel and diving in for another Mediterranean swim. The out-of-the-way spot and sparkling water reminded me of another time when Margie and I departed from the norm. On our first trip to Santorini on an earlier cruise, Margie researched a local swimming hole. We took a city bus from Fira, made our way down a cliff to a tiny fishing village and hiked a half-mile along the coast, where two dozen people were diving from cliffs or lowering themselves into a swimming hole carved between rock formations. Most of the swimmers were covered in tattoos, but we were happily accepted.

You won’t find that swimming hole in any of the ship’s tour offerings.

Convenience of a cruise

There is, of course, much more to cruising than the excursions/adventures. The convenience and ease of cruise travel cannot be overstated. No matter which onshore excursion you choose, you will return to your own room and a restaurant dinner. No schlepping bags, no trying to figure out where to eat.

After our cruise, Margie and I spent a week in Tuscany. Arriving in Florence, we pulled our overly packed luggage along the street until Margie yelled out in agony: “Why would anybody do this?’’ We both desperately longed for our ship cabin at that moment, although the frustration abated when we landed a day later in a gem of a Tuscan hotel, Pescille, nestled in vineyards and olive groves on the outskirts of San Gimignano.

A wonderful benefit of cruising is that when you hit six to eight ports, it allows you to pick a place to spend a week or more if you make a return land-only trip.

My wife very accurately noted that one of the other great benefits of cruising is the chance to meet people you otherwise would have no way of meeting. Our next-door neighbors on the cruise were an engaging couple from Australia, Mike and Bev, both schoolteachers. We had several chat-filled dinners with them, learning a little about their life while relaying the highlights of ours.

Unfortunately for Margie, an elementary school teacher, one of the lessons learned was that the Australian couple’s school system allows teachers to take 80 percent of their pay per year for a five-year schedule that allows for four years of work and one year of vacation.

I was fearful Margie might fall into deep depression at that point. But nothing to worry about: The next day was Santorini.