Very shallow water breathing apparatus

[Degenerate]

Never used a scuba tank and regulator to fill a tire or run an air tool?

No, I have much better suited tools for that so never even thought about it.

Ever seen a deco/safety stop hang bar supplied from tanks on the surface?

No, but now that you mention it I do recall reading about that at least, so makes sense.
Thanks.

 

[tbone1004]

Funny I was reading that. Appealing, and certainly worth looking into...

Anything I can run off of 12v (without an inverter) or even powerless is also appealing. The Google suggestion got me in the right direction. Thank you both .

Would I need pressurization at 5 ft?

Research continues

The general rule of thumb for low pressure compressors is 3cfm/hp. With losses and all of that, you're looking at about 1kw/cfm and for this you need a full 1cfm for 5ft on a hookah. That's a pretty big battery for every hour you need to spend underwater with long recharge times.

You'll be best off with an air tank hookah.
The first stage is exposed to the environment to account for changes in ambient pressure, however the change in pressure between the surface and 10ft is only about 5psi. That is insignificant in terms of the performance of the second stage. If you don't have access to 120v power or a big enough battery bank, the best way to skin that cat is with a long low pressure hose. What I will recommend is that you still wear some sort of harness that you can clip the hose to your chest d-ring or waist d-ring so you don't have the mouthpiece pulled out of your mouth as you move.

 

[James79]

I'm not gonna pretend to know much about regulators, but isn't a first stage supplying you with a certain pressure of gas, based on the ambient pressure around the first stage...?

It is, but for the OP's intended purpose it's immaterial. To put it in perspective, with an intermediate pressure (IP) of 135 at the surface, a first stage would put out approximately 150psi at 32 fsw. If you are using a hookah hose to that same tank on the surface instead, your second stage would behave as though IP had dropped by about 15 psi. That may or may not be noticed on an unbalanced, non adjustable second... but on a balanced second you wouldn't even notice.
Examples are approximations, and my advice is worth what you paid for it!
Respectfully,
James

 

[Subcooled]

That was a thought, but managing the tank (purchasing, maintaining, loading on and off the boat, and especially filling the tank etc) seemed more problematic.

You cannot use a snorkel much deeper than one foot.

You do not want a compressor feeding a constant flow of air either (too expensive).

Your only option would thus be
a cylinder with compressed air + first stage regulator + a long hose + demand valve

 

[Subcooled]

Would I need pressurization at 5 ft?

Now go get a 5 ft plastic tube and test it in a pool.
You will have to overcome some overpressure.
My diving instructor tried and failed.
Your death is not my fault

 

[Bobbyahlers8889]

Haha I appreciate all the input. I think I can just stand up if I'm not getting enough air haha. I hope someone doesn't put their thumb over my straw though, that'd be embarrassing

 

[Ghost95]

Without knowing how much you're willing to spend on the project it's hard to narrow the choices down as there are a bunch out there.

If it were me, I'd go with the simplest solution that I'm comfortable with and that would be a long hose to a tank on deck. If you're only going to be down at 5' for 5 mins. a standard AL80 will be good for many "dives". Older regulators that are easy to service can be found on ebay for relatively cheap and the hose is a one time purchase that should last a long time with just a little maintenance.

On the other hand, if you want to spend a little more, and have a way to recharge batteries then maybe look into this.

Nemo is a compact dive system that supports 1 diver to 10 feet with a rechargeable battery pack that lasts over an hour. Learn more about Nemo here!

It's a battery operated compressor with a 10' hose. The compressor only operates when you take a breath so the battery lasts longer.

Good luck. Hope you find what you're looking for.

 

[M-Cameron]

Spare air?....one of those 6Cu.ft units should easily last 5 mins or so at 5 ft.....hell, you could probably do it with a 3 cu.ft

refill from an AL80 on the surface between jobs?

 

[Akimbo]

Hey y'all, I am looking for some help. I work on boats and lifts , dive a maximum of 5 ft, and need to stay under for a few minutes (less than 5) at a time.

Hmmm, why not take a freediving course to extend your breath holding capacity. You can easily get 2 minutes right out of the class. Tell us more about the work. Are there entanglement issues? What is the water temperature and visibility? Are hand tools involved? Are you after getting weight off for easier ingress and egress, faster gearing up, ... what is wrong with regular Scuba?

 

[Bob DBF]

Hmmm, why not take a freediving course to extend your breath holding capacity.

Although I agree free dive training is a good idea, as soon as the words underwater work comes up I immediately want more air available. It's not that I'm accident prone, but I've had issues, both above and below the surface, which limited my ability to maintain a schedule. This is especially true when working with others and control of the situation is not entirely in ones own hands.