Built for a repeat client and scheduled to appear at the Monaco Yacht Show in September, the 42-metre superyacht Sofia from Moonen comes with a very special feature on the bathing platform: her own three-person submarine. “In 2004 I embarked on a quest to find a high-quality motor yacht that would allow me to cruise the world in comfort,” says her owner. “My research led me to Moonen Shipyards, where I purchased the brand-new Moonen 84 Sofia (now Eleanora). I then commissioned a new Moonen 97. My experiences with Sofia and Sofia II emphasised the quality of design and build of the yard. This third Sofia would be the yard’s largest yacht to date and – unprecedented for her size – carry a private submarine. Although the design started as a two-seat craft, during the construction we switched to a three-seater, which made the challenge even greater.”

The submarine is a C-Quester 3 from U-Boat Worx. At 4.5 tonnes, it is 50% heavier than the two-seat version and required extending Sofia by more than four feet. The greater weight of the new submarine needed a much heavier crane, which has been set into Sofias bathing platform in such a way that it can also be used as a pontoon, providing a base for the tenders and the sub. This unique launching system has been designed to meet all the requirements for Lloyd’s and MCA classification. When the sub is in the water Sofia has a huge bathing platform for diving and watersports.

The yacht, styled by René van der Velden and with an interior by Art-Line, boasts a main deck owner’s stateroom and four guest suites below.