Observations from my second pool session

[TN-Steve]

Had my second (and last) pool session for my OW, going to the Quarry tomorrow to do it in the wild. I've noticed some things, just wanted to share my observations and get any feedback. We had some free time to play in the pool, so I really focused on the things that seem most important.

1. Buoyancy is an ever moving target. I'm 160, 5'8", and was diving an AL 80 with no weight (trunks and a light poly tee-shirt). Tank started with 2100 PSI, and with my BC empty, a normal breath put me at eye level, breathing it out let me sink. So, I'm about right on my weighting. I may even be light, since it was a battle to stay down when the tank was at 600 PSI. Tomorrow that all goes out the window, since I'll be in 5mm of neoprene head to toe.

2. Once at the bottom (9 or 10 feet), a deep full breath would start me moving at a quick pace to the surface, and I'd have to breathe out forcefully in order to stop the process. Empty I could rest at the bottom without moving, but soon as I'd breath, up we would start to drift. Makes perfect sense, and I understand why it's so sensitive at a shallow depth, since the pressure change by percentage is so high due to the shallowness.

3. My best performance in terms of hovering, staying off the bottom, swimming forward as opposed to up and down came when I used a breathing cycle of appx 3 seconds on the inhale, and 6 seconds on the exhale. That kept the up and down very limited.

4. I can't frog kick. At least not without using a lot of energy and moving all over the place. I suspect that I'm doing it wrong. That is something that I'm going to back burner for now, and once I get the OW cert, pick up working on.

5. I may not be an air hog. I started at 2200 psi, finished about 90 minutes at 600 psi, using up 1600 in 90 minutes. Now some of that time was spent at the surface talking to other students, but I had a solid hour underwater. I'm hoping that's good, and expect it to get better as I practice.

6. My finning technique has a LONG way to go, but I wasn't using arms / hands to swim, but did find them useful when turning around at the ends of the pool. Again, I think that with focused practice that will get better.

Just my observations, I may post a similar thread tomorrow after I get back from the quarry.

Have a great day,

Steve

 

[TSandM]

Steve, if you were using a standard BC with an Al80 and no weights, you were probably just about neutral at the beginning of the dive. This is further supported by your description -- if you float at eye level with an empty BC and a normal breath, you are neutral. But that, of course, is with the tank FULL. An Al80 has 77 cubic feet of gas in it when it's full, which is about 6 pounds of gas. You are intending to breath about five of them out into the water, which means, at the end of the dive, you will be five pounds lighter than you were to begin with. If you were neutral at the start, you will have trouble staying down at the end! That's why you could stay on the bottom if your lungs were empty, but you floated up when you breathed. You were underweighted. Hopefully the shop will do better by you on weighting in the quarry.

One of the great things about seeing a post like this is that it's clear that poking around here has given you a huge head up on the average student, in terms of what you should be trying to accomplish. But don't beat yourself up if tomorrow is a bit of a circus. Going from no exposure protection in the pool to thick neoprene in the quarry can be very challenging, and it's quite normal for students to have buoyancy "oopses", and to feel somewhat unstable, when dealing with neoprene and lots of lead.

Come back and tell us how it goes!

 

[NorCalDM]

I agree with what TSandM said you were underweighted and the wetsuit will make a huge difference. Also you should just breath normal most instructors tell you to take long slow breathes but that can make you yo-yo. Pay attention to how you breath above water and I'll bet it's not 3 seconds in and 6 out. After some dives you'll learn to fine tune your buoyancy with your lungs.

 

[Ricky B]

Don't be surprised if your air consumption goes up, way up, when you're in the quarry and a full wetsuit. Every time you enter a more challenging environment, your air consumption will go up. Even if you're an old hand at diving, if it's been a while since you've been diving, your air consumption will go up. Don't worry about that.

Finning technique is another thing you shouldn't worry about for now. I was diving for 30 years before I did a single frog kick. Given the environment I was diving in (resort diving as part of a herd), I don't think that frog kicking would have made a bit of difference.

In silty environments, you will want to master frog kicking. But for now, stay off the bottom of the quarry!