SeeAir - what do you think?
- Thread starter doctormike
- Start date
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OP
Yeah, that I'm not sure about. Most of the other hookah systems I have seen are for more than one diver, while this is clearly not for more than one diver.
Typical tidal volume for an adult is 5-8 liters per minute resting, 12 with light exercise. But I believe it can go up to 100 LPM during heavy exercise. Someone must have data for that with typical diving, and not running a marathon...
Now I don't know how they calculate that rate, or if it is normalized for depth, etc... but it does seem that that would be adequate, even if not normalized, staying above 2 ATA, right? Again, this isn't for everything, and certianly not for dives involving heavy work or exertion.
Green Frog
Contributor
It does look interesting! If I'd had it 15 or so years ago when I was doing algae surveys for CariComp, I could have really benefitted from such a device... I guess we could have used hookah, but we were just using plain old tanks like St Jacques of Cousteau intended! 
Boarderguy
Chief Narctopus Wrangler
Could be useful for culling and harvesting urchins with @Eric Sedletzky
Could be useful for culling and harvesting Darwin Award candidates, lol
How Much Air Do You Really Need?
Depth, pressure, and exercise all effect your breathing gas requirements. Know how to predict how long your tank will last.
dan.org
Breathing Gas Needs: How Much Air is Required to Ventilate Lungs?
| Depth (Feet) | Environmental Pressure (Atmospheres) | Breathing gas Needs (Liters per minute) | ||
|---|---|---|---|---|
| At rest | Light to moderate activity | Vigorous exercise | ||
| 0 feet (Surface) | 1 ATM | 8 lpm | 20 lpm | 70 lpm |
| 30 feet | 2 ATM | 16 lpm | 40 lpm | 140 lpm |
| 100 feet | 4 ATM | 32 lpm | 80 lpm | 280 lpm |
OP
Right, I'm just not sure from those limited promotional materials if they are measuring output at the second stage normalized for depth or not. For a scuba tank, there is no ambiguity, but for a hookah system, you need to specify that...
I looked at several hookah systems and the air delivery spec is always at the surface.
This thing is a toy. If they can deliver what they have promised, it will be fine for looking around in shallow water. But that's about it. Don't expect it to provide enough air for working situations like cleaning boat bottoms or serious harvesting.
OP
I think that "looking around in shallow water" describes about 95% of the recreational scuba market. I mean, I'm not sure I would call it a "toy" just because it might not let you do "serious" work.
Sort of like how the Apple Dive watch got a lot of pushback from technical divers because it didn't do this or that or the other thing. We tend to forget that if you add together tech divers, scientific divers, and working divers together, they sum up to a rounding error in the context of a product that has shipped nearly 200 million units.
Here's another look at the volume requirements. The attached paper defines the work levels in ways that are easily understood. They used a treadmill set at 3.3mph/5.3kmh and varied the grade. Here are their definitions and findings:
Light work (target 40% VO2max) - heart rate 99 ± 9 bpm, average grade 1.5%
minute ventilation mean (SD) = 30.3 (6.2) L/min
Medium work (target 60% VO2max) - heart rate 122 ± 13 bpm, average grade 7%
minute ventilation mean (SD) = 47.4 (13.5) L/min
Heavy work (target 80% VO2max) - heart rate 150 ± 15 bpm, average grade 12.5%
minute ventilation mean (SD) = 72.3 (22.9) L/min
Which suggests that this thing would fail to provide sufficient air to most people at its rated depth even if all they are doing is continuous finning.
Light work (target 40% VO2max) - heart rate 99 ± 9 bpm, average grade 1.5%
minute ventilation mean (SD) = 30.3 (6.2) L/min
Medium work (target 60% VO2max) - heart rate 122 ± 13 bpm, average grade 7%
minute ventilation mean (SD) = 47.4 (13.5) L/min
Heavy work (target 80% VO2max) - heart rate 150 ± 15 bpm, average grade 12.5%
minute ventilation mean (SD) = 72.3 (22.9) L/min
Which suggests that this thing would fail to provide sufficient air to most people at its rated depth even if all they are doing is continuous finning.
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