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Brent Shaw set out to make a boat. Somehow he ended up with a portable submarine
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The Drydive was dreamed up while inventor Brent Shaw was going through chemotherapy treatment

Brent Shaw set out to make a boat. Somehow he ended up with a portable submarine

“So we sailed on to the sun
Till we found the sea of green
And we lived beneath the waves
In our yellow submarine”

Ringo was ahead of his time. So is Brent Shaw. He’s developed the Drydive, New Zealand’s first portable submarine. The original Drydive operates on the surface and down to a depth of 30 metres using a combination of electric and diesel engines.

Shaw is now working on the second model of his prototype submarine, seen at the Hutchwilco New Zealand Boat Show last month. The new sub will be based on the three-man model seen at the show but with improved features, such as more freeboard allowing it to sit higher out of the water.

His original sub, designed and built as a part-time hobby in his Upper Hutt garage, is unique because of its portability. It can be easily towed on a trailer or behind a boat and launched at a regular boat ramp. Passengers enter the sub from the surface then ‘drive’ underwater, giving the sensation of being enveloped by the sea, rather than descending down stairs like other subs.

It also uses ambient pressure, rather than the full pressure of most subs. This means the pressure remains the same both inside and outside the sub. Because the water pressure isn’t working against the hull, construction costs are far cheaper and the windows can be flat and larger than the porthole windows of a full-pressure sub. It’s also easy to manoeuvre, and although anybody can drive it Shaw is imposing his own criteria—operators must have a scuba qualification and a day skipper’s ticket.

Shaw, who works as a production manager for the Hutt News, came up with the idea during a six-month stint of chemotherapy. “I’d already built a car,” he says. “And hot rods. Then I got bored and thought, what am I gonna do now? Originally it was going to be a boat, but then I thought I’d take it a bit further and make it a submersible boat.” What followed were hours of research, then a six-month welding course. “Then I fitted my garage out with a decent stereo system and got to it!”

Drydive had a huge response at the show, where Shaw was taking orders from both local and international buyers. At around $40,000 a pop, they aren’t just for wealthy Beatles. He’ll be producing the new subs with a team of welders and machinists later this year, and Shaw says he can customise certain aspects for the client. “I’ll make them in whatever colour the customer wants. Except yellow.”

Magazine illustrationMonitor relays surface image from CCTVSteering leverClosed circuit TV (CCTV) acts as a periscopeSealed electric motors for underwater propulsionLarge acrylic hatch reduces claustrophobiaTrailer with special Teflon skids to aid launchingHydrodynamic shape to aid manoeuvrabilityLarge windows made from 25mm acrylicElectric motor for running underwater10 horsepower diesel engineDrop Valve fills tanks with water

The new design has more freeboard, sitting higher out of the water than the prototype