There are plenty of small, low-profile cruise lines you've yet to hear of that are ready to take you on an adventure. These cruise lines offer access to unique destinations and often come with perks the big lines can't offer. Here are five great cruise lines you haven't heard of.

Lindblad Expeditions

Credit: @jeff_litton (via @lindbladexp)

Lindblad Expeditions has 12 ships that explore the “world’s most interesting places” in partnership with National Geographic. As Cruise Critic’s 2016, 2017 and 2018 “Best for Adventure” pick, the cruise line staffs each of its trips with scientists and naturalists who explain the nature and wildlife you’re seeing. Academic programs and lectures are numerous. Lindblad travels just about everywhere — North, Central and South America; Europe and the Mediterranean; Southeast Asia and the Pacific; the Polar regions; and Africa and the Middle East. You can also choose to take a photography-based cruise or a multi-generational cruise.

Star Clippers

Credit: @starclipperssailings

The Star Clippers company provides sailing vessels that traverse the Mediterranean, Caribbean and Costa Rica. “Informally elegant,” each ship has local performers in the evenings and other daily activities (navigation classes and knot tying, for example) that pay homage to the sailing heritage of the company. In addition to five- and seven-night cruises, Star Clippers also offers Grand Voyages and Ocean Crossings that last for up to 28 nights.

Australis

Credit: @australiscruises

The expedition cruise company Australis has a small fleet of spacious and beautiful ships that take you to a select number of unique destinations, places like Patagonia and Tierra del Fuego. Each of the line's two ships holds around 200 passengers and runs from September to April, taking three-, four- or seven-night trips through the waterways of Chile and Argentina. Each ship is well-stocked with activities and delicious food. Shore excursions focus on wildlife and nature, and all guides are local Chileans.

Uniworld

Credit: @meaganpotere (via @uniworldcruises)

Looking for a luxurious river cruise to an exotic location? Uniworld is a name to know. Most of Uniworld’s cruises travel to destinations in Europe, while others go to Russia, Asia, India and Egypt. Uniworld has 21 ships that all have the same “daring, dynamic and colorful ambience,” says Cruise Critic. Most Uniworld ships hold 130 guests, and all ships have the highest staff-to-guest ratio in the river cruise industry. Even better, many shore tours are included in the upfront cruise fare, and the excursions are exciting and adventurous — such as touring a German glass factory, visiting a Lisbon flea market and taking a canal tour through St. Petersburg.

Windstar

Credit: @windstarcruises

Windstar Cruises has a small fleet of luxury cruise ships that travel to dozens of locations all over the world — and, as the company points out, the small ships let you get close to the places big ships can’t reach. Each ship has fewer than 310 guests and the ports often have complimentary private events. Windstar prides itself on intimate, personalized shore excursions, such as having dinner at the home of a local family. And your experience on the ship will be every bit as customized and friendly.