Evolve will join 120-passenger ship Connect in the co-branded fleet during the 2027/28 season.

Connect will sail Amsterdam's canals and through the French countryside, while its sister vessel – Evolve – will operate three new festive sailings exploring Europe's Christmas markets as well as another voyage.

Chief executive Natalya Leahy said: “Our river journeys invite guests to see the world in a more intentional way – unhurried, intimate and deeply connected to place. We’re delighted to offer even more ways to explore – including festive European Christmas market sailings."

In May, National Geographic-Lindblad Expeditions's debut river programme – featuring two eight-day itineraries on the Rhine – was unveiled.

Both Rhine River: Castles, Culture and Culinary Delights and Holland and Belgium: Medieval History and Scenic Waterways will be staffed by one expedition leader, several knowledgeable field staff and at least one National Geographic expert.

Field staff will also take guests on private tours and exclusive tastings.

At the time, the line called Connect a "brand-new, state-of-the-art European river ship with cutting-edge technology, luxurious amenities and wrap-around picture windows designed to sail through the heart of Europe’s storied destinations".