We funneled out to Amber Cove, a sparkling $85 million port opened by Carnival last fall. The coffee shops and manicured greenery of the compound gave it the vibe of an upscale mall. But — lest anyone forget why we were there — over 40 percent of Dominicans live below the poverty line. My group of about two dozen filed in to a bus and drove 20 minutes to a recycling plant in a low-income neighborhood where a group of Dominican women have formed a small association that makes crafts from recycled paper to sell. Upon arrival, the employees thanked us, with much applause. We then participated in 20-minute rotations through craft stations: gluing coasters, sewing pot holders, pouring candles infused with insect repellent, sifting paper pulp through molds, and chatting with locals the whole way through. In total I poured 18 candles, made three coasters, sewed one-third of a pot holder, produced one lumpy sheet of recycled paper, and generally got in everyone’s way. After an hour, there was a snack break, during which I talked to fellow passengers. “It’s very emotional, seeing the struggles that people go through,” a woman shared as she unwrapped a sponge cake. “But it’s good to be here,” she added. “It’s good that you’re doing this.”

“Er, thank you?” I replied. (Or: “Ditto?”) I found myself unsure of how to deliver a socially appropriate response. By lunchtime the cruise group had separated into clusters: some were Instagramming, some were buying souvenirs, some were planning to go ziplining or snorkeling (Fathom also offers more traditional shore excursions). On the bus ride back we answered survey questions: What did we most enjoy about today’s activity? What was the most significant thing we achieved today? Our Fathom group leader, who had accompanied us on the ground, shared stats: we made 157 sheets of paper and 300 candles. Not too shabby.

Fathom cruisers plant trees at a nursery as part of a reforestation project in the Dominican Republic.Jeff Berlin/Courtesy of Fathom

Later, after I’d cleaned cacao nibs at a women’s collective and planted tree seedlings, I realized that the sheer metrics of the volunteering — the number of students tutored, the weight of cacao nibs cleaned — was not the point. It is, after all, hardly a stretch to conclude that each of the partnering organizations might have had a more productive morning without being interrupted by dozens of untrained volunteers. Instead, the activities seemed to function as a volunteering gateway drug for people who wouldn’t normally spend their vacation digging holes in a mountainside for the sake of rain-forest replenishment.

And the activities were possibly even a gateway to people, like me, who wouldn’t normally cruise. On Fathom, you will watch Winslow Homer sunsets and eat breakfasts of gemlike tropical fruits. But you may also witness a preteen boy’s first epiphany about global inequality over said breakfast: “We are just miles away from people who are starving and we’re eating at a buffet,” one kid announced to his family, with a look that can only be described as “dawning clarity.” When it comes to souvenirs, that’s worth more than a T-shirt.

fathom.org; seven-night cruises from $499.