The German shipbuilding juggernaut Lürssen is having a remarkable year, and its latest milestone has just passed through the Kiel Canal. The 102.4-metre superyacht Hull 13785—extensively known during its development phase as Project Jassj (and recently named Nixie)—has officially embarked on its initial sea trials, leaving the shipyard’s Rendsburg facility behind to face the open waters of the Baltic Sea.
Sold by Moran Yacht & Ship in 2021 with construction commencing in 2022, this massive 3,420 GT full-displacement vessel is charging hard toward its final delivery window in Q3 of this year.
The Design: Taut Lines and an Unmistakable Deck
While Lürssen engineered the robust steel hull and aluminum superstructure, the interior and exterior styling were penned by the visionary British studio RWD.
Visually, the yacht balances sheer volume with athletic geometry, sporting a cool grey profile punctuated by extensive bands of curved glass. However, its exterior spaces specifically the deck arrangements steal the show:
- The Foredeck Helipad: Topping a traditionally flared bow is a clean, sprawling foredeck specifically engineered as a helipad. When empty, this massive teak-laid wedge serves as an expansive, uninterrupted observation deck, providing 180-degree views when running down down-wind passages.
- The Layered Aft Terraces: RWD’s signature style shines at the stern, where the decks cascade downward in a series of deep, open-air terraces. These levels are designed to eliminate the “walled-in” feeling common on high-volume superyachts, dropping down to a wide, low-profile transom area that connects guests directly to the water line.
Behind the Scenes: What Do Sea Trials Actually Entail?
Sea trials represent the critical buffer zone between a complex engineering build and an official naval handover. For a yacht of this scale—built to carry up to 22 guests across 11 cabins alongside a massive crew of 37—the testing phase is a grueling, multi-day gauntlet designed to push every onboard system to its structural limits.
The Lürssen engineering teams and independent classification surveyors will focus on a few non-negotiable arenas:
1. Propulsion & Speed Runs (The Measured Mile)
The crew will take the 102-meter hull out to deep water to map its power-to-speed curve. This involves tracking fuel burn, inverter behavior, and shaft output over a series of “measured mile” sprints to confirm the yacht hits its contracted top and cruising speeds.
2. Radical Maneuverability & Steering
The captain will execute high-speed Z-maneuvers and crash stops (throwing the engines into full astern from maximum forward velocity). This tests the structural resilience of the rudders, the hydraulic steering pumps, and checks how the hull manages rapid torque reversal under load.
3. NVH Testing (Noise, Vibration, and Harshness)
A “Pinkies Down” luxury experience requires complete silence inside the staterooms. Technicians armed with decibel meters will walk the interior while running at maximum RPM to ensure that Lürssen’s acoustic insulation and floating floor systems successfully dampen engine drone and shaft vibration.
4. Dynamic Stabilization & Harmonics
With a broad 15-meter beam and a deep 3.9-meter draft, the yacht’s stabilizers will be put through rigorous duty cycles. Engineers will test both zero-speed (at-anchor) and underway settings to see how effectively the fins counter ocean swells, ensuring the massive 3,420 GT superstructure remains perfectly level.
