DeepFlight Dragon review: The awesome underwater quadcopter anyone can drive

When you get an opportunity to go fly a 1.5 million dollar electric personal submarine that looks like a Formula One car, but operates like a quadcopter in reverse, on beautiful Lake Tahoe, California, damnit you take that opportunity. Even when you're ten pounds heavier than the maximum weight it's designed to handle. Even when the sub's stabilization software isn't finished yet and the team is still in preliminary testing. Gizmag joins pioneering submarine engineer Graham Hawkes to drive the Deepflight Dragon, a submarine so idiot-proof even Loz Blain can drive it.

If you'd asked Graham Hawkes what he wanted to be when he was a kid, submarine designer wouldn't have been on the list. It was aviation that floated his boat, so to speak, and the wild and woolly early days where inventors like the Wright Brothers would cobble designs together on shoestring budgets, then jump right in and go risk their lives flying the things.

But Hawkes was born too late for aviation. "When I graduated in 1969, aviation had already taken off," he tells me at a marina on Lake Tahoe, California, seemingly unaware of his own pun. "If I was 60 years earlier, I could be building an airplane in my back yard with three wings instead of two, and go and fly faster than anybody else. Now, that's done. Look at Concorde – that took a team of countries."

It was more or less an accident that got Hawkes working on his first underwater devices – a torpedo design job for the British Royal Navy. But he examined the field and thought "they're still making submersibles with wooden skids… Wooden skids! This is where aviation was 60 years ago. I can make a difference here!"

Thus began an absolutely extraordinary career that has taken Hawkes from boom to bust to boom again on the bleeding edge of submarine technology. Time and again he's built and tested his own inventions, a one-man Wright Brothers team pointed down instead of up – and that's why we're here at Tahoe, because he's got a new waterbird ready to fly.

Hawkes has built subs for science, for oil and gas exploration, for deep-sea cinematography, for "hydrobatic flight" and world record Mariana Trench attempts. But they're all highly specialized tools that would be dangerous in the hands of anything less than an expert. He's never tried to build one for the masses.

Until now. The Deepflight Dragon sits before us on the marina platform, drawing a constantly rotating crowd of rubberneckers. It looks like a two-seater Formula One car with vertical thrusters instead of wheels. If you sat it on a helipad and told people it was a flying car, nobody would think twice.

Deepflight Dragon: Drone of the deep

True to recent form, Hawkes' latest design applies aircraft technology to the underwater realm – and when you're looking to build an aircraft so easy your Grandma could fly it without training, there's really only one platform: the multicopter drone. It's simple and stable, it can hover and move around freely, and it's a piece of cake to drive.

In fact, Hawkes first got the idea for the Dragon at an electric aviation conference where he found everyone trying to work out how to build a full-size quadcopter that can carry a man and fly as easily as a drone. "But you can't," he says, "Not yet. It's simple. Math. Energy. Batteries. Endurance. With a drone you have to carry 100 percent of your weight, and a manned drone with batteries just needs too much power. It would have too short an endurance to be worthwhile. But if we take that underwater, we've suddenly got the buoyant force of water, a fluid which is 850 times as dense as air."

So that's what the Deepflight Dragon is: a 2-man underwater drone. It's positively buoyant, so instead of having to lift 100 percent of its weight like a regular quadcopter, it only has to pull downward the equivalent of 5 percent of its weight to submerge. And that means it's basically got all-day endurance on a smallish 15 kilowatt-hour battery pack. The key goal of the project is to make a submarine so easy to drive that any idiot can do it. As your faithful road tester, dear Gizmag readers, I will be that idiot.

Piloting the Deepflight Dragon

My Dragon flight is very nearly cancelled; the team is having some troubles with the stabilization system, for starters – it doesn't exist yet. And what's more, a decade's worth of poor choices has left me about 10 pounds heavier than the absolute maximum weight the Dragon's built to handle. And that's in saltwater. Lake Tahoe is freshwater, so you lose an extra 70-odd pounds of carrying capacity.

But hope springs eternal when the plane tickets have already been bought, and Graham and the Deepflight team pack the back of the sub with highly buoyant foam to try to balance my weight. I'm game; what's the worst that could happen? Cameraman Joe Salas loads up the Dragon with a stack of GoPro cameras as I slide myself down into the rear cockpit and click into my 3-point harness, my feet nudging up into Hawkes' armpits as Deepflight Chief Designer Randall Fletcher runs us through some pre-flight checks.

There's only two controls in the back cockpit: a lever on the left, and a joystick on the right. The lever engages vertical thrust, either upward or downward, and the joystick moves the sub forward and backward, and turns it left to right. It's that simple – and yet it's not quite that simple. An airborne quadcopter tilts forward to go forward and everyone's happy, but since the Dragon is actually pulling downward to get itself underwater, if you tilt forward it'll move backward. Go forward and it'll rear up so you can't see where you're going.

Hence the necessity for a stabilization system to keep the sub on a level plane, and an extra set of thrusters mounted in X/Y orientation under the rear wing. The vertical thrusters' sole job is to control depth and level the sub, the rear thrusters move it and turn it, and everything's hunky-dory as long as the stabilizer system is working. Which it isn't. But we are not descended from fearful men.

We test radio communications, as well as cockpit-to-cockpit Sena Bluetooth headsets. Graham's call sign is Grey Hawk, although he's starting to look a bit more like a white hawk around the sides these days. I go with my quadcopter flying callsign: Bingo Wings.

The marina platform begins to lower us into the water until the seal on the glass dome over my head sinks just below the water level. "OK we have two hatch seals." The team checks the weight balance; the sub's tilted backward a bit, but Grey Hawk is unperturbed: "OK Bingo Wings, it's not ideal but we're going."

And out we go, with the assistance of a diver on our tail guiding the sub out of the marina and past the various boats near the shore. Not that I can see anything, I'm weighing the back of the sub down so heavily that the top of my head's barely poking out over the surface. We find a spot, Grey Hawk pushes forward to engage downward thrust, and with minimal fuss we dip below the surface and start descending, the only sound a rush from the air conditioning and a very slight hum from the propellers. We hit 30, 40, 50 feet under and we can see the sandy bottom of Lake Tahoe on our right.

The Dragon will have a maximum depth of 400 feet, but even 50 feels like a mile under to somebody who's never been that deep before. There's no sign of the surface anymore, save for the winking sun. It feels like another world. Then Hawkes demonstrates the Dragon's most important safety feature, by simply switching everything off as if we're out of power. We slowly float upward, rising along with our own bubbles to meet our reflection in the still surface and break through into the summer air again.

Bingo Wings takes the helm

And then it's my turn. "OK Bingo Wings, I'm switching control to you. You have the con, take us straight down." I push the lever fully forwards, and we gently sink beneath the waves as I become just the eleventh person ever to drive one of these things.

It's not hard. It's not a big deal. Push the lever and descend. And yet that in itself is revolutionary. Traditional submarines rise and fall by altering their state of buoyancy – taking on water, to descend, for example, or pushing water out by releasing compressed gas. It's complicated enough that you need to know what you're doing. The Dragon maintains its state of positive buoyancy, and stays under using constant but gentle thrust. When we get to 40 or so feet under, I pull back to 40 percent throttle and we hover in place.

When it's time to come up, I switch to full upwards thrust instead of letting us float back up. And here our lack of stabilization shows itself. The front end, which isn't laden down by hundreds of pounds of sedentary technology writer, pops up quicker than the rear, which is, and the sub tilts waaaaay back past 45 degrees into a giant, jubilant submarine wheelie.

I consider this bulk fun; I've never wheelied a submarine before. Grey Hawk is less enthusiastic; this is not supposed to be a machine for hooligan thrills. Deepflight has a faster, more exciting craft for that kind of shenanigans, the Super Falcon II. But that machine requires a training course to operate safely. The Dragon is supposed to deliver total calm and confidence for untrained pilots, it's got to be so easy to drive that you could rent one out to your average resort guest. Wheelies are instability. We head back in.

Idiot-proofing the Dragon for sale

Chief Scientist Kip Laws has some good news for Hawkes and the team when we get back on solid ground. He's been working away on his laptop, programming code to plug into the Dragon's accelerometers and ECU to get stabilization working, and he reckons he's got something worth testing.

Kip jumps in the sub with Graham and they take it out into Lake Tahoe again for a few test dives. I sit with the team on the shore, listening in to the radio, which can only work when the sub pops up out of the water. Immediate results are promising – they're able to get around under the surface without tilt becoming an issue, but coming up under full thrust still makes things unstable. Kip changes a few parameters between dives, sitting in the back seat and reprogramming the sub as they go, and within an hour on the water, we get "the big yahoo" – Hawkes is very pleased with progress and invites me to take another drive the next day to feel the difference.

"We can still get instability if we provoke it. I'm just not going to tell you how to provoke it," says Grey Hawk as we taxi out to the deep part of the lake again for my second drive. This time, we go under, then drive forward underneath our diver, who's now so confident in the vehicle's predictability that he's happy to float there as we pass just a few metres beneath him. Using the right joystick, we turn left and right under the water – there's still some roll in effect, because Kip hasn't stabilized for that yet, but the pitch stays very level, doing a much better job of accounting for my hefty butt.

It's a fairly slow and ponderous ride – again, this is not designed to be an excitement machine. It's meant to be idiot proof. In my second drive it proves itself pretty much Loz proof, which is arguably the same thing. In the coming weeks and months, the team will stabilize it for roll, and fit it with a sonar obstacle avoidance system to keep it from hitting the bottom or running into things, and then it'll be just about ready.

The Deepflight Dragon will not sell cheap – it's going to go for around US$1.5 million per unit. Outright ownership will be the exclusive privilege of superyacht owners with the spondoolies to keep an amusement like this on deck for when there's a wreck or a reef to explore nearby. But it's also going to be targeted toward resorts and adventure experience companies, who may choose to run a Dragon as a rental sub for completely inexperienced pilots. It's Hawkes's ultimate goal to open the experience of driving one of these things up to as many people as possible.

Having driven it myself, I'd say that's well within reach. The whole vehicle feels simple, the technology seems almost obvious – that "how come nobody's ever done this before" feeling that comes with so many truly great inventions. Without having driven any other submarines, I can easily believe Deepflight's assertions that there has never been a sub easier or safer to drive than the Dragon.

It's clear that as far as Graham Hawkes is concerned, the Super Falcon II remains his favourite child, but the Dragon has the chance to make far bigger waves. We wish the Deepflight team all the best in their remaining testing and hope the Dragon is the commercial success it deserves to be.

Check out our review video:

Special thanks to Karen and Graham Hawkes, the Deepflight team, Brendan Murphy and our photographer/videographer Joe Salas (4theriders). Also thanks to Mike Hanlon and Noel McKeegan for not having their visas up to date, thus letting this opportunity fall to me. Cheers guys!

More information: Deepflight Dragon