The median age of people traveling with Lindblad is 65, although you'll find people in their 30s and 40s on just about every trip. Lindblad also has a strong commitment to families and believes that families traveling together build relationships and educate future generations about how to care for the planet. As such, the line welcomes children on all expeditions, though families are more common during the summer months, thanks to the line's family-focused National Geographic Global Explorers program available on Galapagos and Alaska sailings.

Ninety percent of Lindblad cruisers are U.S. residents, most are affluent and all are well educated and committed to the environment.

No, there is no dress code on Lindblad and passengers wear casual, comfortable clothing that works best for the destination where they are sailing.

Fares for Lindblad Expeditions' cruises include all shore excursions, except for scuba diving (when available), where a surcharge covers the equipment and the services of a certified dive master. The fares also include the use of onboard equipment, such as snorkel gear, kayaks and paddle-boards. Other inclusions: nonalcoholic beverages, wine and beer at dinner and during the happy-hour recap each evening. Hotels and meals on land may be included depending on the itinerary.

Extra fees include Wi-Fi, crew gratuities (except on select ships) and alcohol outside of dinner and happy hour, though this last one may be included on specific ships.

Forget nightlife and onboard entertainment: Lindblad cruisers gladly start the day with an early shipwide wake-up call and then spend their day climbing in and out of kayaks and Zodiacs to make landings in some of the most remote places in the world, or snorkeling and diving with an abundance of marine life around them. (Some destinations are a little less intense, with expeditions to the Baltic and the British Isles, for instance, to explore the cultural side of the area that is often ignored in quick one-day port calls.)

Kids love the Global Explorers program, which lets them do things like earn a Zodiac "driver's license."

Best for: Active people who are passionate about nature and looking for serious exploration with experts

Not for: Travelers who prioritize room service, TVs and lavish production shows over the destination they're visiting