After years of cramming onto the giant ocean liners of the mainstream cruise lines, a growing number of travelers are turning to smaller ships, drawn by the promise of a crowd-free trip and access to harbors the larger boats can t visit. And where little ships once meant fewer big boat-style amenities, these days more yacht cruising companies are adding outsized perks like spas, gyms and cooking classes.

Little ships now they include perks like spas, gyms and cooking classes.

Here, a look at some popular small ship companies.

Peter Sommer Travels

Passenger Capacity: 2 -24
Specialty Destinations: Turkey

With tours in Turkey, Greece and Sicily, this company specializes in gulets, a type of wooden Turkish boats with 2 to 12 cabins. Sailings include an on-ship guide, who leads passengers on historical and archeological tours throughout the trip. But air-conditioner addicts beware; local laws specify that gulets must shut down their AC overnight.

Photo: Peter Sommer Travels

Lindblad Expeditions

Passenger Capacity: 41 - 148
Specialty Destinations: Galapagos, Antarctica

One of the more educational lines, Lindblad trips include activities like lectures from on-ship naturalists and evenings spent pouring over footage from ship s underwater camera. The company also specializes in Antarctic voyages aboard the National Geographic Explorer, an expedition-class ship that manages to combine the ability to cut through polar ice with creature comforts like a sauna and fitness center.

Photo: Flip Nicklin

Island Windjammers

Passenger Capacity: 12
Specialty Destinations

With just one ship, a 6-cabin tall ship-style schooner, Island Windjammers is by far the smallest company in our survey. But its affordable price (high season trips start at $1,899) and unusual itinerary it makes stops in Bequia, Union Island and Mustique appeal to many Caribbean junkies. Still, some travelers point out that its departure point, Grenada, isn t exactly convenient.

Photo: Destin Bradwell

American Safari Cruises

Passenger Capacity: 12 - 40
Specialty Destinations: Alaska, Mexico

Whale watching is a highlight of many American Safari Cruises trips. Indeed, many of the line s itineraries are all about animal interaction, offering activities like swimming with sea lions or snorkeling amid schools of butterfly fish. Of course, communing with nature doesn t come cheap; American Safari s cruises start at $4,895 for an 8-day trip.

Photo: American Safari Cruises

Ecoventura

Passenger Capacity: 16 - 20
Specialty Destinations: Galapagos

Ecoventura runs its small fleet of 8 to 10 cabin yachts and expedition ships only in the Galapagos islands. But while the company offers limited destinations, it does have a range of specialized trips, like cruises just for divers, female travelers and families. It also promises to cap it s passenger-to-guide ratio at 10 to 1.

Photo: Ecoventura