BREDA – Every day, in a cavernous, brightly lit hall, U-Boat Worx wins its race to the bottom.

In only 15 years, it has wrested deep-sea diving away from science fiction writers, archeologists and naval architects and opened it up to everyone. You’ll see its high-tech subs on large yachts and cruise vessels. Or working for offshore companies, maritime and archaeological research institutes and filmmakers.

Founded in 2005, U-Boat Worx is the world’s largest private sub builder.

It markets half a dozen models that can take up to 11 people to -3,000m. (-9,843ft.). In 2020, the company expanded capacity so it can build 10 subs a year, not counting the NEMO. The lightweight two-seater NEMO stands only 1.55m (5ft) tall and can go down to 100m (330ft) for up to 8 hours. It fits on yachts of under 30m. (98ft.).

“We have a collaborative deal with Italian design studio Officina Armare,” says U-Boat Worx Marketing Manager Roy Heijdra. “They have developed a day cruiser where a NEMO fits on the aft section. That’ll stretch our market past superyachts and cruise ships.”

The NEMO will soon be the world’s first serial-produced sub. Its €1 million price tag includes a 12-day pilot-certification course at U-Boat Worx’s Curacao training center. Weighing only 2,500kg (5,510lb), the NEMO is the world’s lightest manned sub. It can be towed behind a car on a trailer and launched from shore.

U-Boat Worx’s Superyacht Sub 3 is for +30m (+98ft.) boats, can drop to -300m (-984ft.) and accommodate three people. “With a height of 1.75m (5.7ft.) and weighing 3.8 tons, it fits perfectly in a superyacht’s tender garage,” says Heijdra. “We have sold several and have several in our order book.”

For very high-end cruise vessels, U-Boat Worx makes craft like the Cruise Sub 7 that can take six passengers and a pilot to -300m. (almost 1,000 ft.). U-Boat Worx’s C-Researcher caters to archeologists and is highly adaptable. A 3-person version will soon go on a Damen Yachting expedition yacht and can go to -1,140m (-3,740ft). Built for a documentary maker, it’ll carry advanced underwater cameras and lights and can stay down for eight hours.”

The C-Explorer 3 and the new C-Researcher series are stable craft. “You can hang anything on them,” says Heijdra. “One or two gripper arms, sonar, extra lights. Anything! But for us, a depth of 3,000m (almost 10,000ft) is a magic limit. At that point, the acrylic in the bubble becomes really thick making the submarine heavy.”

Like a scuba vest, U-Boat Worx subs have a buoyancy control device. The more air is added to an inflatable bladder, the more buoyant the sub becomes. Let air out, and the sub becomes less buoyant. If all electronics fail, says Heijdra, there is always enough oxygen, and the sub will rise automatically. Pressure in the bubble is always 1 bar. “It’s like sitting in a plane, but without the noise.”

The DNV GL classification society verifies U-Boat Worx subs whose acrylic spheres are made in England. They have super-strong, Dutch-made, high-alloy Duplex steel hulls whose welds are all  X-rayed.” 

www.U-Boat Worx