One of the most salient facts about the Galapagos is that each island is home to different variations of the animals that populate the archipelago; it’s those circumstances that led Charles Darwin to develop his theory of evolution. Visiting only one or two islands misses the point, and the best way to check off a greater number of them is to take a cruise. That doesn’t condemn you to life on a floating city as it might in the Caribbean, as there are more and more cruises offering intimate experiences, bringing you to more than a dozen stops across eight different islands.

The Galapagos have been Ecuadoran territory since 1832, and Ecoventura is one of a number of local companies doing business in an increasingly internationalized environment. Today, Royal Caribbean, Lindblad, and National Geographic all operate cruises there. While Ecoventura has been operating for over three decades, the increased competition has spurred the company to redevelop its fleet. The Origin was introduced in February 2016, and the Theory in March 2019. A third ship, Evolve, is due to enter service next February, completing the trio. Ecoventura also sought out membership in the Relais & Chateaux organization to help assure visitors of a luxury experience and were inducted into the organization in 2018.

A panga-load of guests depart the *Theory* for a hike at one of the archipelago’s many sites.

The new ships offer state-of-the-art facilities, including a hot tub, well-appointed cabins—all with sea views—and comfortable dining and common areas. What they aren’t is big, which is actually a virtue in the Galapagos. All three ships carry 20 guests when sailing at maximum capacity. Gigantic cruise ships are not permitted in the Galapagos, but some vessels carry up to 100 passengers. While the larger ships capitalize on economies of scale to offer a higher level of service in some respects, they don’t get you any closer to the animals of the islands. The government carefully licenses and monitors where tourist ships can go, and all companies, small and large, are restricted to the same set of sites.

Additionally, disembarking from a large ship can take a half-hour or more, while 20 passengers can board a pair of Zodiacs, or pangas, as they’re known locally, and be headed to the next beach, hike, or snorkeling spot in five minutes. That means more time with the actual experiences that are unique to the Galapagos: witnessing blue-footed boobies in their peculiar mating dance, watching sea lion pups cavorting on the volcanic rocks, or snorkeling alongside the world’s only marine iguanas. One also enjoys those experiences in smaller groups, without the next landing party pushing you on to the next stop.

One of the islands’ endemic land iguanas looking up from its lunch.

Ecoventura makes the most of what nature offers by providing a very low ratio of guests to guides. The Galapagos National Park, which makes up 97% of the land in the islands, requires at least one guide for every 16 guests. Every Ecoventura ship carries two guides, which is at most a 10-to-1 ratio if every guest takes part in an excursion.

Aside from this individualized attention, it also means groups can be divided according to interests or energy levels. Guests excited for a more strenuous hike to the top of a caldera won’t be held back because other guests aren’t in shape for it. The highly trained guides educate guests not only on the islands and the animal inhabitants but also on the efforts underway to protect them.

According to Ecoventura’s CEO Santiago Dunn, most of the agency's guests are North American, and the average age has skewed increasingly younger over the past two decades. Keeping in line, the primary audience has become increasingly aware of the environmental issues surrounding their visits. Ecoventura first began embracing green initiatives 20 years ago, signing on to an initiative led by the Rainforest Alliance and an Ecuadorian NGO, Conservation and Development; the World Bank began supporting the program a few years later.

“We were the guinea pigs,” Dunn says. “With the World Bank, we did the Smart Voyager program, the first green seal for tourism in the Galapagos.”

A Galapagos tortoise giving a seemingly enthusiastic welcome to visitors on Santa Cruz Island.

The program set out guidelines for sustainably supplying vessels, improved training and treatment of staff, and instructions for guests designed to minimize environmental impacts. The efforts have faced challenges. For example, certification required a recycling program; while Ecoventura implemented the program on its ships, all waste went to the island’s municipal facilities, which didn’t activate recycling initiatives until 2006.

With the new fleet, the company has implemented additional green strategies, including diesel engines that run at lower revolutions per minute (RPMs) to reduce fuel use. (It doesn’t make them that much quieter, so packing earplugs if you’re in a rear cabin is not a bad idea.) Moving from short cruises to longer ones (at least seven nights) was also an environmental move.

“Longer trips means less of a footprint,” Dunn says. “Someone who picks a destination, be it the Galapagos, or Machu Picchu, or wherever, to say, ‘I was there’ and only stays one or two nights, that’s a traveler we want to avoid. We want the traveler that comes here and wants to be part of the solution.”

A pair of blue-footed boobies engaged in their mating dance.

It’s a work in progress: Ecoventura’s ships are fitted with desalination machines producing perfectly drinkable water, but that doesn’t deter some guests from insisting on bottled water, for example. Passionate guides and well-trained staff can do a lot of the convincing. The company offers guides in particular a number of benefits, including private shipboard accommodations, and also keeps them to two weeks of touring a month to avoid burnout.

After centuries free from major predators, the animals of the Galapagos are remarkably trusting of humans. Ecoventura’s team says it not only helps guests honor that trust—allowing them to get inside the life of the tortoises, iguanas, and birds of the islands as they go about their daily lives—but that they also lead guests to a place where they want to deserve it.

More must-read stories from Fortune: