At 190 passengers, Tui Aria is the highest-capacity ship in the company's river cruise fleet, and will be sailing Rhine and Moselle rivers from Amsterdam, Basel and Frankfurt this summer.

"The ship itself is modern, but with a focus on relaxation and a really great home-from-home feel for our guests," Berzins said.

Tui Aria is also the first in the fleet to feature an all-weather pool with a retractable roof. The space, Reflections, has sunloungers, a sauna and an Italian dining offering in the evening.

"We're really excited about Reflections, which is a totally new venue for us," Berzins continued. "But we've also brought in a mix of customer favourites from across the fleet, so guests have lots of options for how they want to spend their holidays."

The Observatory, the ship's main bar providing nightly entertainment for guests, and Verdastro, offering a mix of local and international dishes for breakfast, lunch and dinner, are two other key onboard features.

The launch of Tui Aria marks an "evolution" of the brand's scale and concept, insists Berzins who also told TTG Tui is seeing couples in their 20s and 30s sail on its vessels.