The demand for river cruises has been growing at an annual rate of 10-15% in the last decade , with travelers increasingly seeking more luxurious and sustainable options. If you ask Viking CEO Torstein Hagen what he’s most excited about when it comes to the future of his long-running, top-rated river cruise line, it’s not the Tulip Season river tour from Antwerp and Amsterdam or its new 2027 trip along India’s Brahmaputra River. It’s the Viking Libra , set to be the world’s first zero-emission hydrogen-powered ocean cruise ship and developed in partnership with Italian shipmaker Fincantieri. “People said it couldn't be done, but we're doing it,” Hagen says. Already under construction, the Libra is scheduled for delivery in late 2026 with the next hydrogen ship Viking Astrea scheduled for 2027 . Its eco-minded practices aren’t the only thing that sets Viking cruise line apart. “We have small ships. We don't allow children. We don't have gyms or casinos.…