Diving with just a Pony. 4-8 Metres.

[EIREDIVER]

I'm looking for advice on this diving equipment.
This is what I own:
13mm Semi-dry. Boots, gloves, hood.
Northern Diver ''Power fins''!! (regular Fins).
Regular mask.
I first dived in 2018.
I have been training to dive since last October.
I have recieved my CMAS* Certification and unfortunately due to the quarantine, diving has
come to a halt.
I live beside a lake and intend on cleaning litter from it, this is the rig I'm about to buy:
SoprasSUb Bailout Pony Bottle Diving Kit with Nylon Belt - Hose - 13 cf Tank - SPG Gauge - Regulator - Fill Adapter - Spare Secondary Air Scuba Dive Egressor
https://smile.amazon.co.uk/LCM-Pres...keywords=air+pump+scuba&qid=1588104347&sr=8-5
If I buy that equipment I'll work with different weights and try to figure out an adequte constant boyancy.
I wouldn't be exceeding 8metres depth, Averaging out at 4metres. I dont plan on staying down for long.
With the 1.9L tank, I'm hoping for 15-20 minutes. If I reach 8metres as assigned by my gauge (I found a
2nd hand wrisit guage on ebay) I will factor in a 3 min stop. Open to any help on the matter.
Thanks for reading.

 

[saxman242]

There's no way that first link isn't a scam. That price doesn't check out for a tank, reg, etc, even if they're utter crap.

Given the dive profile you're talking about and some loose assumptions about your air consumption, you'll get maybe 5 minutes of bottom time on a 13 cu ft tank at 10m.

You're not going to pump up a 13 cu ft tank with a foot pump like that either. Assuming their numbers are correct (which I highly doubt), it's going to take a solid hour+ oif constant pumping to fill the tank for 5 minutes of bottom time.

I'd suggest you derail this train of thought, revisit your training, and get a real tank.

 

[James79]

Regardless of suitability of that particular set-up, have you done any calculations on required gas for the dives you want to do, and do yo know your RMV (respiratory minute volume)? For example, that's a 13 cf, 3000 psi tank. 500 psi reserve is only 2.1 ish CF, and still only leaves about 11 CF usable gas. I'm an air hog, at .75 ish CF a minute. At 10 meters (32 feet), I'm at 2 ATM (BAR) so my gas consumption is 1.5 CFM. So for me, that 13CF tank would only be a 7.3 minute supply, with a 1.5 minute reserve. Your RMV may vary, and I don't know enough to say it's not a good idea, but make sure you are aware of both the system limitations, and yours!
Respectfully,
James

 

[EIREDIVER]

There's no way that first link isn't a scam. That price doesn't check out for a tank, reg, etc, even if they're utter crap.

Given the dive profile you're talking about and some loose assumptions about your air consumption, you'll get maybe 5 minutes of bottom time on a 13 cu ft tank at 10m.

You're not going to pump up a 13 cu ft tank with a foot pump like that either. Assuming their numbers are correct (which I highly doubt), it's going to take a solid hour+ oif constant pumping to fill the tank for 5 minutes of bottom time.

I'd suggest you derail this train of thought, revisit your training, and get a real tank.

Hmm, It's quite hard to revisit training at the moment. I think this direction is the best for continued training considering the limitations. Thanks for the advice. I initally planned on purchasing this rig : https://smile.amazon.co.uk/gp/product/B082F5DK13/ref=ox_sc_saved_title_1?smid=AQJKBNT0IR63H&psc=1 . Perhaps it's a better option? I'm not going to derail from the thought, The pier needs to be cleaned.

 

[saxman242]

I'm not going to derail from the thought, The pier needs to be cleaned.

I didn't say derail from cleaning the pier.

Derail from using the wrong equipment.

That kit will probably at least show up, but it's still a horrible choice for what you're trying to do.

Use the right tool for the job.

 

[EIREDIVER]

Regardless of suitability of that particular set-up, have you done any calculations on required gas for the dives you want to do, and do yo know your RMV (respiratory minute volume)? For example, that's a 13 cf, 3000 psi tank. 500 psi reserve is only 2.1 ish CF, and still only leaves about 11 CF usable gas. I'm an air hog, at .75 ish CF a minute. At 10 meters (32 feet), I'm at 2 ATM (BAR) so my gas consumption is 1.5 CFM. So for me, that 13CF tank would only be a 7.3 minute supply, with a 1.5 minute reserve. Your RMV may vary, and I don't know enough to say it's not a good idea, but make sure you are aware of both the system limitations, and yours!
Respectfully,
James

Thanks for the reply James.
I meet the UKDMC guildelines for diving, this included 3 seperate medical examinations. Even If I got 10 minutes at 4metres I would be satisfied. The gear isn't expensive as I'm a student, the gears purpose is to allow me to continue training and to be comfortable in the environment. It's purely a novel stepup from rec snorkelling.

 

[saxman242]

I meet the UKDMC guildelines for diving, this included 3 seperate medical examinations.

What does this have to do with knowing your RMV rate?

 

[EIREDIVER]

I didn't say derail from cleaning the pier.

Derail from using the wrong equipment.

That kit will probably at least show up, but it's still a horrible choice for what you're trying to do.

Use the right tool for the job.

What would the right tool be? Any gear recommendations would be great. As a student I don't have much funding, this gear appears to allow me at least 10mins at 4 metres.
Consider what I'm doing as novel snorkelling.

 

[EIREDIVER]

What does this have to do with knowing your RMV rate?

SAC 27.50 / RMV 0.73
that's my RMV. These are results from my UKDMC tests. Looking for help, thanks saxman

 

[Edward3c]

I'm looking for advice on this diving equipment.
This is what I own:
13mm Semi-dry. Boots, gloves, hood.
Northern Diver ''Power fins''!! (regular Fins).
Regular mask.
I first dived in 2018.
I have been training to dive with my university since last October.
I have recieved my CMAS* Certification and unfortunately due to the quarantine, diving has
come to a halt.
I live beside a lake and intend on cleaning litter from it, this is the rig I'm about to buy:
SoprasSUb Bailout Pony Bottle Diving Kit with Nylon Belt - Hose - 13 cf Tank - SPG Gauge - Regulator - Fill Adapter - Spare Secondary Air Scuba Dive Egressor
https://smile.amazon.co.uk/LCM-Pres...keywords=air+pump+scuba&qid=1588104347&sr=8-5
If I buy that equipment I'll work with different weights and try to figure out an adequte constant boyancy.
I plan on diving with my course (science) and I've been assigned a position on my clubs committee, so I'm pretty determined to build up experience.
I wouldn't be exceeding 10metres depth, Averaging out at 5-6metres. I dont plan on staying down for long.
With the 1.9L tank, I'm hoping for 15-20 minutes. If I reach 10metres as assigned by my gauge (I found a
2nd hand wrisit guage on ebay) I will factor in a 3 min stop. Open to any help on the matter.
Thanks for reading.

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.