13 cuft pony for duck dives. Is it possible?

Ok, so i'm in the middle of a project that i've had on my mind for a very long time. Basically, i want to sling a 13ft pony w/ regulator under my arm for snorkeling/lobster diving. The plan is to do normal snorkeling, with a light weight belt, and do normal freediving descents and ascents while holding my breath. And then, when i find a spot that i want to explore, i can dive down and get a few minutes of bottom time, and then ascend. I know i will be positively buoyant, but that's ok, i will be holding on to the rock because of the surge anyways. I am going to practice with it in a pool first, and need to get good switching between holding my breath on the normal duck dives, and breathing during ascent with the pony.

I know this idea is unorthodox, but that's the way i think. Please don't bash this just because it's different, i want some real, constructive criticism. I'm fully prepared for this idea not to be feasible, and I put safety first. Thanks for the advice in advance!

I would be concerned that while switching back and forth between breath hold and SCUBA that you might open yourself up to a lung overexpansion injury by accidently holding your breath on ascent after breathing off the tank.

exactly, that is the primary thing on my mind with this setup. I mentioned that earlier. That's why i want to train with it in the pool first.

I don't believe that you should ever hold your breath and freedive, then switch to compressed air as you may feel necessary. You need to go one way or the other. Freedive or scuba. Not both. Experts also frown on doing recreational freediving after scuba diving on compressed gases, which may bring on DCS...I'd check this out with your local scuba instructors to get their viewpoints...just my two cents...stay safe!

Unsafe idea! :11:

Imagine diving with that little air, trying to make it last as long as possible... You breath slowly. You tend to hold each breath a little longer to save air. Then, as you've exhaled all your air you feel the imediate sensation of an empty tank, but it's not a warning. It's just empty, because this tank is so small... And then on completely empty loungs you make your way to the surface. But you are heavy without the air in your loungs, so it takes much longer than usual... Great, huh?

This is not a good idea. Stick to regular scuba diving or train to be a good freediver. Do not try something in between.

I dunno....really it depends on how compartmentalized you might be in your head.

I can easily see a scenario where you go snorkeling essentially to recon a site. You conduct a series of free dives/breath-hold dives to determine whether the site might be productive if you were, for example, looking for lobsters.

But - at least in my concept - you would be rigged for diving, in terms of being weighted properly and wearing a 40 cu ft aluminum tank or steel 72 at a minimum.

You're doing the snorkeling thing essentially to recon where along a specific ledge or wall or drop-off you want to conduct your dive. Once you select a location, then you actually conduct a dive.

It may be a matter of defining terms, but you're doing one thing first, and then another thing second - you're not switching between the two at random.

In the case of mixing snorkeling with scuba I can see where any lapse of awareness may cause injury or worse. But assuming you are able to clearly differentiate one from the other, and are snorkeling before (and after, as desired) a "dive" which you clearly define as such, I can see where you could mix the two activities in order to maximize your productivity.

For what its worth...

Doc

Let me say this... Last winter I was at a dive site and started with a skin-dive. As I was doing much more scuba diving than skin-diving at the time guess what I absent mindedly did? I made a nice duck dive down to about 15 feet and as my buoyancy stabilized I began to inhale! In my mind I had slipped below the surface and there was a regulator on the end of my mouthpiece. So I'm living proof that switching between two is not a trivial undertaking.

Another concern of making these extended stay skin-dives is the number of ascents you may make. Doing it once or even a few times from minor depths is one thing. A significant number of such dives to significant depths (admittedly vague) could set you up for subclinical DCS (excessive weariness) or worse.

All in all I'd be most concerned about confusing the practices of the 2 activities. In the worst of times it's those automatic behaviors that can save you. Intending to work on hybrid diving in the pool is a very wise precaution.

Pete

Thanks for all your guys' input so far. The responses have been exactly what i expected. Everyone's saying be extra careful! hahaha. Trust me, i know it's always a good idea not the be the "test pilot" for something that's esentially underwater life support, but i've thought this through a lot and i believe i have made myself aware of all the things i need to look out for. You guys seem to be thinking on the same page as me, and telling me to be super-careful about mixing up which i'm doing. Trust me, that's been concerning me as well. One of the things i do that will help is that when i snorkel, i take my snorkel out when i duck dive, so i'm not used to having a snorkel in my mouth underwater, only a regulator. Also, i wouldn't free dive, and THEN put the reg in my mouth underwater, that would be crazy. I'd do recon duck dives, and then put the reg in, and descend with fin power. Also, i will be doing this in water no deeper than 30 feet.

Really, the reason i'm doing this is because diving in san diego is about as tough as it gets in terms of beach entry. The rock and the surge here make it a PAIN to gear up and scuba (not to mention parking). I live 1 block from the water, and would like to walk down and swim around sometimes.

As long as you are certified, why not just strap on a full sized tank and save the energy for catching diner. What is the benefit of combing the two?