The appropriately named Super Sub by U-Boat Worx has completed sea trials in Curaçao ahead of delivery, marking a step forward for private underwater travel with higher speeds, deeper dives and advanced safety systems. Robbie Hodges reports

U-Boat Worx has completed sea trials of its new Super Sub, with delivery to its first client expected within weeks following testing in the waters off Curaçao. The company describes the Super Sub as the fastest private submersible it has built, combining higher speeds with extended range and updated onboard systems.

The Super Sub was tested through a series of manoeuvres designed to assess propulsion, handling and safety performance. The trials took place off the coast of Curaçao, where the company also captured photography and video of the vessel in operation. According to U-Boat Worx, the programme confirmed that the submersible meets required safety standards and is ready for client delivery.

The Super Sub has a top speed of nine knots and delivers 100kW of horizontal thrust. It can operate at depths of up to 300 metres and has a range of up to ten nautical miles. The craft is also capable of steep inclines and descents of up to 45 degrees, allowing it to move more freely across underwater terrain compared with traditional submersibles.

U-Boat Worx says the Super Sub is designed to behave more like a performance vehicle than a conventional underwater craft. During testing, engineers evaluated how the sub handles acceleration and directional changes underwater, with a focus on smooth movement and control. The company notes that hydrodynamic lift plays a key role in how the vessel moves, enabling what it describes as a more fluid underwater experience.

Safety systems were a central focus during the Curaçao trials. The Super Sub is equipped with a sonar system that continuously scans the seabed and adjusts the vessel’s trajectory automatically. This allows the craft to approach depth limits in a controlled way. Redundant life-support and control systems were also tested to ensure reliability during operation. The sub has received safety approval from DNV, a global classification body.

Inside the Super Sub, passengers sit within an acrylic pressure hull designed to provide wide views of the surrounding ocean. The cockpit layout is arranged to support both pilot control and passenger visibility, with an emphasis on maintaining clear sightlines during dives.

The Super Sub is intended for use either as part of yacht programmes or as a standalone exploration vessel. Its speed allows for wider areas to be covered within a single dive, while its manoeuvrability supports closer inspection of underwater features such as reefs and shipwrecks.

U-Boat Worx, founded in 2005, has built more than 60 submersibles for private, research and commercial use. The company focuses on combining safety systems with new approaches to underwater mobility, and the Super Sub represents its latest model in this category.

With testing now complete, the Super Sub moves into its final preparation stage before handover. The company positions the vessel as an evolution in private submersibles, shifting the focus from endurance and access towards faster, more responsive underwater travel.