Diving with just a Pony. 4-8 Metres.

[saxman242]

What would the right tool be?

A real tank with a useful volume and a trustworthy regulator.

Some well researched, pre-owned purchases will put you in a much better place for the same cost.


If we take your rmv of .73 to be .73 ft3/min and add a reasonable factor for cold water diving/any stresses for dealing with getting snagged on something, a reasonable planning value is about 1.5 ft3/min. That tank is a 13 cu ft, however, if you're going to surface with 500 psi per your training, you've only got about 11 cu ft to play with (assuming you started with a full 3000 psi fill).

At 10m, your effective rate for planning is 3 ft3/min. You'll have a little over 3 minutes of useful volume, ignoring any ascent time/safety stop/etc (which you definitely shouldn't ignore).

 

[EIREDIVER]

The tank is 1.9Lt. Even at 200bar you’ll have around 15 minutes at the surface or 7 at 10m.
The pump, if it worked, would give you wet fills with all the problems that would produce.
Just accept your going to have to wait to finish your training, and importantly how to plan diving.

P.S. With your SAC you won’t get the times I quoted.

I'm far too stubborn to do that! Thanks for the advice, I'll look into a bigger tank. If all fails at least I'll have a pony for when I'm back with the club

 

[Vitesse2l]

Hi Eirediver,

If you trained since last October then you probably haven't done much diving in open water, or solo (forgive me if I've got the wrong end of this stick). My last sea dive was November and I'm going to do some pool refresher training before anything else. I'd take the time to revise what you learned and see how that fits in with your clean-up plan. I know its only shallow but I have been doing dive rescue management training this evening so what-ifs are fresh in my head.

What sort of rubbish are you planning to remove? Some of it makes good homes for sea critters.

 

[saxman242]

If all fails at least I'll have a pony

At least buy a useful pony then. A 13 cu ft pony is basically only useful as a compromise between a pony that can fit in carry on luggage while flying to remote places vs not having a pony at all.

 

[EIREDIVER]

Hi Eirediver,

If you trained since last October then you probably haven't done much diving in open water, or solo (forgive me if I've got the wrong end of this stick). My last sea dive was November and I'm going to do some pool refresher training before anything else. I'd take the time to revise what you learned and see how that fits in with your clean-up plan. I know its only shallow but I have been doing dive rescue management training this evening so what-ifs are fresh in my head.

What sort of rubbish are you planning to remove? Some of it makes good homes for sea critters.

Thanks for the advise. That's correct, I have only 4 logged open water dives. Rescue diving is something I hope to persue in the future, that's impressive work. Until now I've been snorkelling with the gear I own. I plan on cutting old fishing lines and rope from the rocks, removing cans, plastic bottles etc. I have been cleaining beaches with the marine society in my uni and have found it to be a meditative task. Are there any rubbers I should look out for? Thanks for the reply.

 

[Edward3c]

I'm far too stubborn to do that! Thanks for the advice, I'll look into a bigger tank. If all fails at least I'll have a pony for when I'm back with the club

What I didn’t include is the proposed pump will not have the filters to remove any nasty gasses that under pressure become killers.

 

[saxman242]

That's correct, I have only 4 logged open water dives.

You really ought to get some more experience under your belt before you take on task loaded, solo dives, with limited air.

I get that you're new and excited, but you're running head on into Dunning-Kruger, and what you don't know will kill you.

 

[rmssetc]

... I have only 4 logged open water dives. ... I plan on cutting old fishing lines and rope from the rocks, removing cans, plastic bottles etc.

Or, putting it another way, you could say:

I plan on a high chance of entanglement, a high chance of stirring up silt and suddenly reducing visibility to zero, a chance of being in an obstructed environment under a pier, encountering broken glass, rusty cans, etc.

Get a proper tank. At least that'll give you plenty of time to sort out the mess.

 

[Scraps]

Eirediver,

Trying to protect and clean the marine environment is something good divers strive to do, so I commend your intentions.

However, everything else about your plan is inconsistent with how good divers plan. Please don't do it.

First, good divers dive within the limits of our training and experience, and we try to add only one extra level of difficulty or complexity or newness at a time until we have mastered it and are ready to build on it. In your case, you're an inexperienced brand new diver attempting to dive with unfamiliar nonstandard gear, to dive in low visibility with risk of entanglement, to dive in unfamiliar water without a local guide, to add extra tasks, and to dive solo. That's not just pushing the envelope--it's shredding and burning it.

Second, good divers understand that water is a foreign environment that can kill us, so we endeavor to identify and mitigate the risks we will encounter. We would never say, "Hey, it's just ten meters," because many people with more experience and better gear than you have died in less than ten meters of water. You're creating a situation in which, if everything goes right and there are no surprises, you might not die. It would be far better for you to create a situation in which several things could go wrong and you'd still survive.

I understand and sympathize with your financial constraints. But those constraints should not motivate you to attempt something that is such a dramatic departure from your training and from prudent practice. Wait until you can rent or borrow suitable gear. Wait until you can team up with experienced partners. The trash will wait for you to prepare to do this dive safely.

Best wishes,

 

[davehicks]

If you can't buy a used Al80 tank for $50 you are not looking hard enough.