Lindblad Expeditions is retiring two of its U.S.-flagged ships, the National Geographic Sea Bird and the National Geographic Sea Lion.

According to a recent press release, the 62-guest sister vessels will be replaced by the larger Greg Mortimer starting in 2027.

Built in the early 1980s at the Nichols Brothers Boat Builders yard in Washington, the small ships are currently the longest-serving vessels in the company’s 12-ship fleet.

Originally ordered by Seattle-based Exploration Cruise Lines, the then Great Rivers Explorer and Majestic Alaska Explorer were acquired by Lindblad in the early 1990s.

The Sea Bird and the Sea Lion have since spent most of their summer seasons in Alaska while offering U.S. river and coastal cruising during the shoulder seasons.

Other itineraries visited by the vessels include Baja California and Magdalena Bay on Mexico’s Pacific Coast.

In 2026, the two ships are scheduled to start the year in Baja California before repositioning to the Pacific Northwest for cruises on the Columbia and Snake Rivers. The 360-ton vessels are then set to offer summer cruises in Alaska through early September.

The Sea Bird and the Sea Lion will return to the Columbia and Snake Rivers for their farewell seasons, sailing in the region through late October.

In addition to Alaska and the Pacific, the ships have sailed around the East Coast in the past, with itineraries visiting the Hudson River, South Carolina, the Chesapeake Bay and more.

Currently in service for Aurora Expeditions, the Greg Mortimer will take over the vessels’ itineraries in Alaska starting in 2027.

Built for SunStone Ships in China, the 180-guest ship was delivered in 2019 and is set to operate summer seasons for Lindblad through at least 2029.

In addition to the Sea Bird and the Sea Lion, Lindblad’s American-flagged fleet also includes the National Geographic Quest and the National Geographic Venture.

The 100-guest vessels were also built by the Nichols Brothers Boat Builders yard and entered service for the company in 2017 and 2018, respectively.