Nine knots underwater. That’s the figure that makes the U‑Boat Worx Super Sub impossible to ignore — three times faster than most personal subs, quick enough to keep pace with dolphins, and a speed that fundamentally changes what private submersibles can do.

“Precision at your fingertips,” says U‑Boat Worx of its hydrofoil controls. Credit: U‑Boat Worx

The Super Sub isn’t a speculative concept or a glossy render. It’s real, certified, and about to be handed over to its first buyer. U‑Boat Worx, the Dutch company behind it, has been building luxury submersibles since 2005, but this one is different. At 21.3 feet long and 10.8 feet wide with wing‑like stabilizers, it’s designed for agility as much as endurance. Four rear thrusters, each paired with a pilot‑controlled hydrofoil, deliver up to 100 kW of horizontal thrust. That’s what pushes it to its 9‑knot top speed — roughly 16.7 km/h — while most competitors, including Triton’s personal subs, max out at 3 knots.

Inside, the cockpit seats one pilot and two passengers beneath a panoramic acrylic canopy. The view is amplified by a powerful lighting system that illuminates wrecks and reefs hundreds of feet below. The vessel is rated to dive to 1,000 feet (300 meters), with a hyper‑precision sonar system constantly adjusting trajectory to avoid hazards. It can ascend or descend at angles up to 45 degrees and carve turns of 30 degrees, maneuvers that would be impossible in slower, bulkier subs.


62‑kWh battery, eight hours below. Credit: U‑Boat Worx

Power comes from a 62‑kWh battery pack, enough for eight hours of operation and a range of 10 nautical miles. That endurance is backed by a 96‑hour emergency life support system, tested during certification trials in Curaçao. Oxygen supply, CO₂ scrubbing, and backup power are all built in — not luxuries, but necessities when you’re hundreds of feet underwater.

What happens when private explorers can dive at military speeds? Credit: U‑Boat Worx

The Super Sub’s journey to market has been deliberate. First shown at the 2023 Monaco Yacht Show, it underwent sea trials and safety certification by DNV before U‑Boat Worx announced readiness for delivery in March 2026. The company hasn’t disclosed the exact buyer, but the price is public: €5.2 million, or about US$6 million. For perspective, that’s ten times the cost of U‑Boat’s smaller Nemo model and several times more than many hypercars.

U‑Boat Worx Super Sub, certified for delivery at €5.2M. Credit: U‑Boat Worx

Speed underwater has always been a dividing line. Military subs can exceed 40 knots, but they’re built for stealth and combat. Civilian craft rarely break 3 knots, prioritizing safety and stability over thrill. The Super Sub shifts that balance. It’s not just faster; it’s nimble, with hydrofoil‑controlled thrusters that give the pilot fingertip precision. That combination of speed and control is what makes it stand out — not a gimmick, but a new category of private exploration.

Calm waves above, 1,000 feet of pressure waiting below. Credit: U‑Boat Worx

The first handover is scheduled for this week, marked by a countdown clock on U‑Boat Worx’s site. For the buyer, it’s the start of a hobby that blends luxury with technical mastery. For the industry, it’s proof that personal submersibles can evolve beyond slow sightseeing bubbles.

Nine knots underwater — faster than dolphins, yet passengers sit in silence. Credit: U‑Boat Worx

What happens next is the real question. If one customer is willing to spend millions for speed and maneuverability, others will follow. And once more of these subs are in the water, the definition of private ocean exploration will change. Not just drifting through coral gardens, but racing alongside marine life, diving steep angles, and treating the deep sea as a place for motion, not just observation.

Sources: New Atlas, U‑Boat Worx