Voluntourism is a term referring to travel with the purpose of volunteering in some manner upon arrival at the destination. Passengers can either find their own volunteer opportunities in ports their cruise visits, or can work with groups like Hopefloats.org that provides volunteer opportunities as excursions in select ports.

The idea behind cruise voluntourism is that passengers can spend a portion of their cruise vacation lending a helping hand in ports of call. The work can be as simple as helping at an animal shelter or participating in a beach cleanup, or as challenging as working on a construction project.

Even fun activities like recording fish populations while snorkeling or scuba diving or spending a day working at a donkey sanctuary can have a positive impact on cruise ports of call.

Carnival Corporation previously operated a one-ship cruise line, known as Fathom, dedicated to voluntourism in the Dominican Republic and Cuba. That ship, Adonia, is no longer sailing under the Fathom program. Going forward, Fathom will be used to brand voluntourism experiences onboard six of the corporation's cruise lines.

Luxury cruise line Crystal Cruises operates a program called "You Care, We Care" that offers a range of free shore excursions in select ports that allow passengers to participate in volunteer efforts that include animal welfare, renovating schools and environmental conservation efforts.

Other cruise passengers take extra bags of needed clothing or school supplies along on their cruise for drop-off in ports. Still others make the effort to shop or eat at locally owned stores and to purchase locally produced goods -- all with the goal of giving back and leaving cruise ports just a bit better for having hosted the cruise.