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Scuba-Doo Underwater Scooter
hawado writes "Just when you thought it was safe to go in the water, 'Fans of the Segway scooter now have a way to look just as silly traveling underwater as they do on land thanks to the efforts of an inventive Australian company.' 'The Scuba-Doo comes with everything you would want in a submerged Segway.' I just don't know what to say, but I am sure all you /.rs will have some really great comments. The company's web site can be found here."
I've done it - snuba is more fun, but this can be less intimidating for inexperienced people.
these things have been around for a while, and I think they are a bad idea. I am a current SCUBA instructor as well as a pretty experienced cave and technical diver. There are so many limitations to this thing that makes it completely impractical. Transport is one issue in terms of getting it into and out of the water.
for one thing, inexperienced pilot will have this hard bodied device with which to crash into delicate coral. this will have to be used in a body of water with typically little current, else it become quite easy to lose the group.
It cannot go deep for long since it is still open to ambient pressure, so decompression comes into play as well as gas supply. For every 33 feet (10m) one descends, the pressure increases by one atmosphere. If that tank were to last the diver 60 minutes on the surface, then at 33 feet it would last only 30 minutes, at 60 feet it would be 20 minutes, and so forth.
It might be ok for a few shallow water, shore-based resorts that can charge the units at the dock. Even a fairly cheap diver scooter will be just around 800-1200, and those can only go to about 100-150 feet if you're lucky. In order to go more deep, you have to get more specialized units (www.gavinscooters.com) that can handle the pressure (I've taken mine to 350) and has the battery burn time. Even those units only cost ~$3500. These units are simply torpedo looking devices that tow the diver. The biggest advantage is that it reduces the workload for the diver, thus dropping air consumption and helping one cover more ground.
This device has no similarities other than someone trying to compare two unlike things with a vague attempt at seeming technologically advanced.
Cave, wreck, and deep diver.
The real problem is that at 10 meters you dont want to be staying under water for anything more than about 60 minutes, due to nitrogen build up. You are still breathing pressurised air, as you do in scuba - it is not a pressure vessel like a submarine where you are breathing atmospheric pressure. Therefore you will be subject to the same dangers and limitations that a scuba diver faces. A dive computer can track the nitrogen better and gove you longer (and more exact) dive times, but the safety margin is then reduced. A 15 meter dive would rarely be longer than 45 min. 30 meter dive: 20 min or so, depending on your exact dive profile.
Here are the dangers facing both a scuba diver and a scuba-doo pilot:
1) Nitrogen buildup, which limits the duration and depth of a dive. Even with unlimited air, you have this problem as your tissues become saturated with nitrogen. The deeper you go, the faster you absorb nitrogen ( because the partial pressure of nitrogen is greaer). if you get too much, it is no longer posible to come up to the surface in case of an emergency, or you will get the bends. If you get too much nitrogen in your system, you effectively have a "ceiling" over your head that you cant go through, and you might as well be diving in a cave or something. Recreational diving tables are designed so that this never happens. (ie. you never have to do a decompression stop)
although usually you do a 3 minute "safety stop" at 5 meters to reduce this danger still more.
2) below about 18 meters, you will start to get the effects of Nitrogen Narcosis. This effectively is like having a couple of beers or a spliff or something, and affects both your judgement and motor skills. When I did my rescue diver course, I had this demonstrated to me with an excercise:
Do some simple calcs on a slate just under the surface, and again at 18 and 30 meters. It took twice as long to do calculations at 18 meters compared to just under the surface. The deeper you go the worse the problem gets, and if you are not experienced with it it's easy to go dancing with the mermaids or go chasing those pretty alien lights down the abyss.
3) It is still possible to get air embolisms if you hold your breath as you are surfacing. If you are holding 1 litre of air in your lungs at 20 meters will become 2 litres of air at 10 meters and 4 litres at the surface.
That's why divers spend time in a classroom - not to learn how to put on their fins or something, but how to survive when in a totally alien environment. This training shouldnt be skipped, as all the same risks still exist.
The dangers, especially the air embolism ones are still there even between 0 to 10 meters. infact, the airembolism ones are greater in this depth range, because the pressure(and hence volume) changes so rapidly over the short distance. At greater depths, say for going from 40 to 30 meters, the volume change is only about 20% (ie. 5 atm -> 4 atm) instead of 100% (ie. 2 atm -> 1 atm).
Oh, and by the way, the Scuba-doo factory is just up the road from my house. The things look a bit like those BMW scooters that have an enclosed canopy.
Second when you dive to a depth of 30 to 60 feet or so you can only stay down safely a bit less than an hour or you risk getting the bends (nitrogen saturation of your blood coming out in gass form in your joints and nerves). So the time limit is just fine.
Third you dont have to be certified to use this. fourth, its failsafe in many ways that scuba is not. The number one danger in scuba is forgetting to exhale when ascending (descending is not dangerous). If you forget to exhale on ascent from 60 feet then when you get to the surface you have a few atmospheres of air in your lungs and they literally explode inside of your body. Since ther is a bubble of air around your head there is no time when you would feel like holding your breath. This machine automatically passively equalizes the air pressure for you as you ascend (your nose is also exposed too).
Likewise there is no way to suddenly find the tank is empty. when the tank goes empty you still have a head bubbles worth of air left
One of the little known facts about scuba diving is that if you run out of air then if stay calm you always have enough air in your lungs to swim to the surface from any depth. The reason is that as you go deeper you also have more air in your lungs. You only have to remember to exhale on the way up to let off the excess air pressure.
this thing is attached to a bouy so you cant sink it or goo to deep go into a cave. And you have a lifeline to the surface if you are disoriented. When you get to the surface you have floatation.
A final danger in scuba is too rapid of an ascent. when you try to go up your boyancy device will run away from you: as it expands you rise faster leading to further expansion and pretty soon you are apolaris missile broaching the surface as your lungs go "pop". On the scooter it controls this for you.
On the other hand the joy of scuba diving is the freedom of 3-D orientation. Drift in a current head down. try to use as little effort as possible (e.g dont swim up but instead just control your breathing to control your veritical position). look behind you look all around. This sort of sucks the life out of the sport.
Some drink at the fountain of knowledge. Others just gargle.
Have you even seen the damage done by a cruise ship dragging anchor across the ocean floor?
Have you even seen a 3000+ year old reef destroyed by some offcourse barge?
Do you know that most of the reefs at popular dive destinations are DYING?
The last thing we need are a bunch of inexperienced divers crashing these underwater vehicles into table corals, soft corals, and otherwise speeding up the demise of our fragile coral reefs.
Think I'm exaggeratting?
Freighter damager 1200ftX200ft swath of Florida reef
60% of great barrier reef hit by bleaching
Great barrier reef 50 years from death
Sewage killing Tobaggo's reef
Bottom trawling fishing destroys large portions of deep water coral reefs never explored
You're joking right ? Puking through a regulator is no harder than puking any other way, and I know from personal experience.
As an added benefit you would be amazed at how all the beautiful fish swarm round you afterwards.
If you dive without scuba gear, the problem cannot happen. You cannot have any more air in your lungs than you started with at the surface. Think about it. Your lungs will feel slightly crushed when going down, and expand back to normal size when going up. No problem.
Incidentally, you cannot have any more nitrogen in your tissue than you started with at the surface either. That's why the guys in Le Grand Bleu were able to go down to a depth of 100 meters, and up again whithin a couple of minutes, without feeling the bends.
The danger of scuba is that you add air (and nitrogen) to your body while at depth, and this air will expand in your lungs if you go up.