Personal Submarine Cruises SF Bay

LandSonar writes "Graham Hawkes, the guru of the submarine design business, tried out his new submersible sea plane yesterday in SF Bay. Called the 'Deep Flight Aviator'. Article and cool pictures. This craft doesn't use ballast like traditional subs. Flys more like a plane. 'It looks like something NASA might build or the Blue Angels might fly.'"

Comments

No Ballast?

[zer0vector]

If the submarine doesn't use ballast to maintain its depth, it must always be in motion to stay at a depth away from equilibrium. Assuming it is positively bouyant (it floats) the motion of the water over its dive planes would be the only force holding it underwater. This seems a bit limited to me, since you'd never be able to stop and enjoy the view underwater. It's probably because I'd be more interested in the stuff sitting on the bottom of the ocean, rather than the things moving through it, which appears to be the point of the sub.

Re:No Ballast?

[neksys]

The article states that, when the submersible drops beneath "stall" speed (approx 1.2 knots), a conventional ballast system kicks in to maintain dive depth - making it perhaps more versatile than conventional submersibles, as opposed to the limitations that you suggest.

exciting!

[jericho4.0]

"When we get up alongside sperm whales or giant squid it will get really exciting," he said.

When I'm in a submarine, I don't want anything exciting to happen.

Deep sea for everyone!

[bravehamster]

Deep Flight Aviator will revolutionize exploration by making it easier and cheaper for everyone from scientists to filmmakers to plumb the ocean's depths.

Oh, you mean like the same people who do it now? What about me, average joe six-pack? When can I go dive down that there Marianas Trench? I want to see the Giant Squid in it's native environment and stop the Discovery Channel from doing anymore of those specials where they don't find the damn thing...again!. Is this deep sea diving for the masses, or just an upgrade for those who already do it?

Re:Deep sea for everyone!

[FatHogByTheAss]

When can I go dive down that there Marianas Trench?

Not Marianas, but you can certainly go explore SF Bay. PADI or NAUI should be able to connect you with the right people.

SCUBA is the best thing you'll ever do with your clothes on.

Seaquest!!!

[Monofilament]

WOW Seaquest is coming true.. I wonder if it comes with an ultra smart dolphin who has a translater hooked to it so i can have conversations with it.

Damn I completely forgot about that show before i saw those pictures...

Extreme high pressure...

[neksys]

According to thei creator's website, they are planning on creating Deep Flight II, which they hope to pilot to the bottom of the Mariana Trench, some 38,000 feet down. But wouldn't the intense pressure and high viscosity of the water at that depth make it nearly impossible to operate on the flight principle? I don't know the first thing about high pressure underwater maneuvering, so perhaps someone else can tell me why this will (or won't) work?

Re:Extreme high pressure...

[RoundTop-VJAS]

well... the flight principle would work at those depths. Assuming the parts can stand the pressure (what they are trying to get done). even though the pressure has changed, the resistance of the water will be essencially unchanged. (since the propellers will be biting more in the water, producing more thrust, this will ofset any drag problems). Since it is designed to cut through the water rather than force its way through (conventional sub) it should work.

The problems at 39k feet are following:

#1) materials that can stand up to it. I'm sure that a piece of solid metal can, but can the cockpit? #2) If anything goes wrong...ANYTHING. you are dead. #3) Making sure your seals can stand the pressure (any that rupture - see 1 & 2)

However if the cockpit can sustain the pressures (since it is smaller than a full regular sub it should be able to take more pressure.) then it should be able to hit those depths no problem. Not only that, but at the proposed dive/accent speeds they might have to worry about the bends. at 400ft/min to go 37,000ft would only take 1.5h. All the "modern" subs/deep subs take much longer than that to hit those depths ('cept some military ones...but they don't go as deep [as far as we know])

This concept has actually been around for a while, however I give massive kudos to these guys for pulling it off not once, but twice. I watched the documentary on discovery about Deep Flight and that was cool. DF Aviator is definately a step in the right direction as it gets rid of the classic sub image.

As for increasing the speed for more than 6knots.. that is a simple equation.

Running time = battery power / draw of props (increases as revs go higher)

So either increase the battery capacity (for the same weight) and speed for the same running time. Or you will sacrifice run time.

Eg: To make it go ~12knots it would take roughly twice the battery power, reducing its effective time from 8h to 4h (I know there are more things..but that is the major factor).

Another technique is to increase the size of the props. But that takes more energy to get them spinning (for more thrust though).

Re:Extreme high pressure...

[pclminion]

According to thei creator's website, they are planning on creating Deep Flight II, which they hope to pilot to the bottom of the Mariana Trench, some 38,000 feet down. But wouldn't the intense pressure and high viscosity of the water at that depth make it nearly impossible to operate on the flight principle?

The pressure would pose a problem, but, contrary to what you might expect, the viscosity of water actually decreases with pressure, until around 150 MPa of pressure. After that, viscosity starts increasing with pressure.

That pressure corresponds to about 50,000 feet of seawater. Since (as far as I know) there is no trench this deep on Earth, we probably won't be having problems with viscosity anytime soon.

Water is definitely one of the most unique substances we have on this planet.

Re:Extreme high pressure...

[BLAG-blast]

I'll try and dispell some myths for you rather than just calling you dumb.

Since it is designed to cut through the water rather than force its way through (conventional sub) it should work.

There is no difference between how this submarine moves through the water and how a "conventional sub" would move through the water.

Making sure your seals can stand the pressure

Any rubber seals are just for the first few feet. After 30 feet the water pressure will be creating a metal to metal bond (or metal to acrylic or what ever) so the seals will not do anything. If you're refering to the metal to metal bond as a seal, then you kind of right, but any problems would have notice at around 30 feet. As you go deeper the bond will just get stronger.

Not only that, but at the proposed dive/accent speeds they might have to worry about the bends.

The bends only apply if you are exposed to outside pressure. This is a 1 ATM sub, you are always at the same pressure as you where on the surface.

Eg: To make it go ~12knots it would take roughly twice the battery power, reducing its effective time from 8h to 4h (I know there are more things..but that is the major factor). Another technique is to increase the size of the props. But that takes more energy to get them spinning (for more thrust though).

This isn't really true either, it would probably be more like a quarter of the endurance for twice the speed. But they might be other things limiting the speed such as drag, the sub isn't a very hydrodynamic shape and might have a low terminal velocity.

More cool Small Submarines

[TheLurker]

For more cool homebuilt submarines, check out the Personal Submersables web page.

Strange picture...

[NanoGator]

I bet somebody could cook up a hilarious caption for this picture.

"The bionic dorsal fins aren't what scares me, it's the frickin laser beam attched to it's head!"

Re:Strange picture...

[Anonvmous Coward]

"http://www.sfgate.com/chronicle/pictures/2003/01/ 24/ba_sub04.jpg"

Man I'm tempted to make a rude Kenny Baker joke.

Feh.

[cporter]

I still want one of these.

"The ultimate personal transportation device, 65 meters (213 ft.) in length with 470 square meters (5000 sq. ft.) of interior space on 4 levels. As proposed, the submarine would constitute the single largest private undersea vehicle ever built."

A Cheaper Alternative

[Bowie J. Poag]

If anyone from San Francisco (or California, for that matter) is looking to see the bottom of the SF Bay, I can help you. I have plenty of rope and quick-dry concrete, and I'll be happy to help you experience the natural wonders only the sea can offer.

Cheers,

Possible problem

[ELCarlsson]

"They wear khaki coveralls with lots of zippered pockets"

Okay, so you're 150 ft under the water when you're homemade sub springs a leak. And what are you wearing to save you? Khaki coveralls. Sure hope they have something helpful in one of those zippered pockets.

Re:Plans?

[Reality Master 101]

Yeah! I even got a name for you: how about "The Suicide Express"? "The Widowmaker" is already so overused.

build your own sub

[paughsw]

This team at Virginia Tech, (I used to be on it) are the three time world champs for a human powered submarine. Check them out, lots of cool videos, and documentation. www.hps.vt.edu

has been done before

[floRizla]

This thing is not as original as it seems.
If you know the comic books of Tintin, there is one album where Tintin and his friend (ship cpt. Haddock I believe) explore the sea in a shark-shaped submarine. It has very much the same shape as this thing, including the windows that have the shape of a half sphere.

So, one of the co-inventors is Belgian comic designer Hergé. And Possibly Leonardo da Vinci too, for that matter.

How long til these are outlawed?

[Anonymous Coward]

A cheap, small, personal submarine, capable of carring two people--or one person and 200lbs of drugs from Mexico or Canada into the U.S.A. (or 200lbs of explosive, or ...)

Watch the U.S. Coast Guard build lots of sonar installations. Watch the ecologists sue the Coast Guard for what all that sonar does to the sea life.

Watch Congress outlaw personal submarines.

It is a common misconception that penguins. . .

[kfg]

can't fly. You even see them refered to as "flightless" birds in the text books.

The fact is that they don't fly * in air.*

Watch a penguin "in flight" and this idea is just as obvious as flying machines in air are from watching a hawk soar. I'm only surprised that it's taken this long for someone to actually go ahead and build one.

Nor is the concept unique to the water. There was an experimental plane some decades ago that was a zeppelin shaped like a flying wing. It was heavier than air, but only by a matter of pounds and flew by the lift produced by its wing shape, but was nonetheless dirigable.

I can find no reference to this plane on the web (surprise, not everything is recorded on the web, go figure) but New Yorker magazine once did a piece on it.

The basic principles of buoyancy and lift apply to any fluid medium. All the rest is just commentary and you can find "planes," "zeppelins," "blimps," and even "helicopters" in the natural underwater world as inspiration. Just as you can in air.

KFG

Bull: Re:Buoyancy and "flight"

[WolfWithoutAClause]

Unlike in true flight, where it doesn't require more energy to maintain an altitude of 2000 feet than 1000,

Yes it does, the air is thinner up there.

it takes incomparably more energy to maintain a depth of 2000 feet compared to 1000 if you're not using buoyancy control.

A submarine displaces its own volume of water, and has a lift proportional to the difference between its weight and the weight of that volume of water at that depth. The density of the sea water hardly varies between the surface and the bottom (the pressure goes wayyyyy up, but water is largely incompressible), so the buoyancy is nearly the same.

Therefore the amount of energy needed is largely the same also; independent of altitude, for a fixed volume submarine, since you're only really fighting buoyancy to go down.

Also, in flight a wing uses reduced air pressure above the curved top of the wing surface (Bernoulli's Principle) for most of its lift. Does anyone know if this effect applies in water? Intuitively it seems like it would not.

Gee, I don't know, mister; ever heard of a propeller? That's a set of wings that rotate under water. Get a clue.