Reasons to take a propulsion/trim/buoyancy class...

[The Chairman]

Based on my limited underwater physics, does forward mean I move the tank band down the tank so that the BC is lower relative to tank valve?

Think in terms of the diver being prone. In this case, yes, the BC would be lower on the tank, because the tank would be further forward. I often do this in the pool with the BC still on the student.

EDIT: One of the biggest things that seemed to really hurt my enjoyment of diving though was actually my control on the surface. Sounds stupid I know, but I was never able to find a way to get myself setup so that on the surface waiting for the boat, I could just float there. I always tipped forward facedown into the water, and on rough chop days it was downright scary. Do these classes typically address that at all, or is it all bottom skills?

Every class should be tailored to the needs/wants of the student. It should never be a large class, so there should always be latitude to address those times that you feel out of control. Not all of these classes are equal and not all instructors care equally either. Choose carefully.

A dry suit class is always a good thing to take. Here in Key Largo, mselenaous does a great job getting you squared away.

 

[bluehole]

Diving is it's own worst enemy, we dumb down the classes to get certified, turn out masses of under educated diving, and then whine about reef beaters and silt kickers. Make up your minds, can't have it both ways.

 

[Diving Dubai]

What a great thread!

For my little input, I've worked consciously hard over the last 8 months to improve my diving technique. The predominant reason for this has been that my G/F and dive buddy has 200+ more dives than me, and I've been wanting to improve my air consumption to match her dive times. My club has a high proportion of instructors from all different agencies and we dive most weekends, so there are plenty of people willing to dive with you, watch you and advise accordingly. Our club encourages people to go for the BSAC standard and aim for goldand a personal pride thing. I often go away for 2 day trips, and because I only have two cylinders of my own (15L lightweight steel) end up using these, 12L steels and 12L Aluminium cylinders over the 2 days, so am always changing weights (currently zero with the 15's)

Although I was pretty happy with my buoyancy a recent live-aboard was a bit of an eye opener as well as making an improvement to my diving. Firstly I was diving with 13L Aluminium cylinders, at the start of the week I was okay at 4kg but by the end of the week was down to 1kg Part of that was the self pressure of Diving with only 13L @200bar and trying to eek out 1 hour as I'm used to normally diving 15L @ 230 bar. By the end of the week I was chilled out and was down to 1Kg and easily getting a 1hr dive time.

Watching others and their flailing about underwater certainly gave my ego a boost as I wasn't - I can just float around with my camera and be pretty stable - even more so now. The other lesson I learned was from the dive guide, where on boarding the boat the majority of divers ask for a certain weight almost like a security blanket.. indeed the guide would normally insist after the first dive leave 1 - 2kg behind (some did some refused and he would take it form them while they were't looking - in ALL cases by the end of the week the divers were diving less weight then they believed they needed thus air consumption was much improved as was buoyancy.

Another thing I noted was people reacting to perceived depth changes rather than actual - they thought they were sinking or rising based on what they were seeing from the underwater topography and dumping or inflation accordingly, rather than looking at their computer which most often would be telling them something different, they would also make big changes for immediate effect rather than a little change and waiting (and watching their computer for their actual change to register).

The two biggest indicators of proof for me post Live aboard is that I'm now diving 12L steels rather than the 15's and ending a dive with similar or greater air reserve than I did and my computer logs are showing a nice flatish line with a small sinewave for depth changes due to breathing rather than the bigger spikes of old. Off to attempt the Black standard this month

BRONZE: minus or plus 2m (Ocean Diver standard)

SILVER: minus or plus 1m (Sports Diver/Assistant Instructor standard)

GOLD: minus or plus 0.5m (Dive Leader/Instructor standard)

BLACK: minus or plus 0.3m (National Instructor/First Class Diver/technical diver standard)

 

[The Chairman]

Diving is it's own worst enemy, we dumb down the classes to get certified, turn out masses of under educated diving, and then whine about reef beaters and silt kickers. Make up your minds, can't have it both ways.

Such a broad brush! You've never seen one of my students then.

 

[The Chairman]

During a conversation with a non-diving spouse recently, I found another reason to pursue such a course: Your significant other dives, but you don't enjoy it! (I'll edit the first post to include this)

We were on an evening cruise on the Island Dream, a paddle wheeler here in Key Largo. It was part of the recent REEF event, so almost everyone was a diver. Almost. I sat across from a guy who was happy to let his girl friend dive without him. He was certified, but he just didn't enjoy being under water. I just had to find out why, and so I pried a bit. He was pretty open about it, but he couldn't quite put his finger on it. At one point I asked him if he felt out of control during the dive. At this point his eyes opened wide, he pointed his finger at me and exclaimed "That's it!" He just didn't feel like he was able to control his buoyancy to the point of being safe or even comfortable. What a shame! I truly feel that a class like this would be perfect for these kind of people.

 

[divingpyrate]

Good thread, we go for ours next weekend
Private class, just my wife and daughter and I
One day pool, one day in a scuba park in Terrell, tx

Sent from my A500 using Tapatalk 2

 

[The Chairman]

Be sure to post a class report!

 

[The Chairman]

Here is my current outline of the class I teach... It got a little morphed this past weekend.

Propulsion, Trim & Neutral Buoyancy Class​

(Oodles of Snobbish Trim Class)
​

Confined water:

• Establish static trim and buoyancy
• 30-60 second blind hover
• Master the elements of the frog kick
• Stop, maintain depth and turn without the use of hands
• Demonstrate Scuba skills while neutral (mask off, air share, BCD doff & don)
• Buddy breathe length of pool (no change in depth)
• Set the BCD for diving
• Descend & ascend without using BCD inflator (breathing yourself down and up)
• Pick up weights without using BCD inflator (micro control of buoyancy by breathing)

Open water:

• Plan the dive(s)
• Demonstrate anti-silt techniques at all times
• Demonstrate good buddy skills at all times
• Demonstrate appropriate buoyancy and trim at all times
• Set the BCD for diving
• Descend & ascend without using BCD inflator (breathing yourself down and up)
• Navigate 30 meters by compass, return on the reciprocal heading and find your starting point (stay within 2 foot of the bottom)
• Negotiate a 10ft underwater obstacle using only your breathing
• Deploy and inflate a sausage from depth with line attached (no more than 3' variance)
• Calculate SAC after the dive(s)

Edit: What would you like to see included/excluded from this?

 

[LowDrag]

Are you mad!? The water out there must be freezing! To be fair i've been told that the diving here in Vancouver is actually really good.

Maybe in a dry suit, but I never learned to dive with one of those (and that is even more buoyancy to deal with!), and i'd have to rent since I don't own one.

My dry suit course was one of the easiest courses I have taken. After learning how to get out of a feet first ascent I felt really comfortable in my DS. My wife and I both dive White's dry suits and neither of us had the issue of "re-learning" our buoyancy all over again. That is not to say that our buoyancy is perfect by any sense of the word but we definitely did not have a learning curve to beat like most divers talk about when going from a wet suit to a dry suit. Check out White's, you can find some good deals on them and it will open a new world of diving for you.

To NetDoc,

Thanks for starting this thread, I have learned quite a bit from reading it and will keep following it. I met a lady who is an instructor in Vancouver Washington (Just few miles from home) that does a PADI PPB class that sounds a lot like yours. I have been considering taking it and this thread has got me thinking that it is a definite must. I am definitely foot heavy and I will be trying to correct that this weekend when diving with my wife. Balancing my rig and my wife's will be on the top of my priority list this weekend.

 

[The Chairman]

I met a lady who is an instructor in Vancouver Washington (Just few miles from home) that does a PADI PPB class that sounds a lot like yours.

Good for you. Send her a copy of my skills list and see what she thinks. There are a number of instructors teaching this syllabus or a variation of it. Here is a description of PPB from the PADI website:

• How to trim your scuba gear so you’re perfectly balanced in the water
• Nuances in determining weight so you’re not too light nor too heavy by even a slight degree
• How to streamline to save air and move smoothly through the water
• How to hover effortlessly in both a vertical position and a horizontal position

I don't have their standards in hand, but I don't see much on propulsion or a few other skills in there. However, it's my personal belief that it's the instructor that's important. A competent, caring instructor will make sure you accomplish your goals regardless of the agency they teach for.