Hapag-Lloyd Cruises will launch both vessels in 2019, aiming at the five-star expedition sector.

The identical ships will be 16,100 tonnes, with a passenger capacity of 240 in 120 cabins and suites. Both will be primarily aimed at the German-speaking market, but Tui has confirmed that one will also carry clients from the UK, US, Belgium, and Netherlands.

The Norwegian-built ships will have three restaurants, a spa and fitness area, seven decks and high ratio of balcony cabins.

The crew ratio will also be high, with a maximum complement of 170.

The vessels will have the highest PC6 Polar Class designation, meaning they can cruise the Arctic and Antarctica as well as warm water destinations such as the Amazon.

On-board Zodiacs will allow landings in otherwise inaccessible expedition areas and the ships will also feature a water sports marina.

Both ships will launch in 2019, with one in spring and the other in the autumn.

They will join the line’s existing expedition vessel Bremen as well as its luxury cruise ships Europa and Europa 2. The announcement comes as the company celebrates its 125th anniversary.

Karl J. Pojer, Hapag-Lloyd Cruises’ chief executive, said: “We are perfectly positioned in the luxury market with our cruise ships Europa and Europa 2. In the anniversary year, we are charting the course for the future. We already operate successfully in our expedition segment, which offers growth potential for 5-star cruises.

"Our new-builds will help us to further develop the expedition segment and offer a modern interpretation. They will also serve to strengthen our leading position in this market, in particular at the international level.”