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

[aeweems12]

Successful for you I want to hear about because I am always looking to steal new ideas, successful for me is under different parameters, and there are real reasons why parts of the approach you lay out fails to result in positive outcomes in direct to ocean training because it pretty much immediately results in negative feedback, or ingraining bad behaviors.

Well I would say that I had some very good behaviors ingrained while taking this course. Neutral buoyancy was taught to me in the pool and it was directly translated to diving in the ocean.

I agree completely with TSandM, I started on the surface and let air out of my BC until underwater. The times I was pushing myself off the bottom was when I wasn't neutrally buoyant and at NO time did I push off from the bottom hard enough to go back to the surface. It took some time in the pool and a dive or two to really "get" neutral buoyancy. Once I did, my third dive I spent completely relaxed. I never touched my inflator and I came up with almost 1000 more psi in my tank than the previous dive and the dive was only 8 minutes shorter.

FloridaPhil, Imbodie, and pocky21 - you will never regret taking NetDoc's course

 

[ferris213]

I have played with the walking in trim along the bottom until neutral is established.

What does this mean? How can you be walking along the bottom while in trim??

 

[The Chairman]

If you have proper trim, will you naturally settle in a horizontal position when relaxed? Or does it mean you stay horizontal when relaxed, AFTER you get horizontal?

It's a balancing act. Many divers have a weight rearward bias, causing their feet to naturally sink. The first thing we do in the pool is to adjust your weight so that it's centered. The first few minutes are all about adjusting your tank and/or adding trim weights to achieve this balance. After that, it's a piece of cake. Actually it's more like a piece of crumb cake. Yummy, yummy crumb cake. That means you can choose your attitude easily in the water column simply by extending or bending your legs. If you want to go up, it's easy enough to stretch out and pivot your head up and the opposite can be done to go down. When you are butt heavy, you have to struggle to maintain a horizontal trim and most simply fail. I don't understand why instructors don't correct this on the first confined water session so that their students can be comfortable during the entire class.

Once balance has been achieved, you can achieve a neutral buoyancy that sticks with you the entire dive. You won't sink when you stop. You won't feel the need to scull either. You won't have to constantly play with your BC. You'll use far, far less air since you aren't fighting your trim all the time. It's easy, it's fun and it makes you look like a pro when peeps see you underwater. As one SBer puts it, you'll have snobbish amounts of trim. That's something to be actually proud about.

There are two things working against people enjoying a perfectly horizontal trim. The first is their field of vision. Lie flat on your belly, with your knees bent. Now look straight ahead. Ah! It's tough to look straight ahead, isn't it? Now tilt your head to one side and try. It's not perfect and I do a lot of looking left and right while I dive.

Second, consider your attitude right now. You're probably sitting in a chair and are mostly upright. When you want to go somewhere, you stand and walk, again staying mostly vertical. Most of your conscious life is spent vertical. Getting horizontal is not normal. Mind you, it's always fun, but it takes getting used to. Make no mistake about it, there are times when I get vertical in the water, like when I ascend. That's what is natural and safe for me to do as I approach the surface with all those hard hulls and sharp propellers buzzing about.

 

[guruboy]

I am bottom heavy. I can get a diagonal trim but it's hard to go/stay full horizontal, especially if I have jet fins on.

The two factors I'm playing with now:

1) Trim weights on tank band (I use 4lbs total, all in trim). Is it bad to overweight myself to help forward balance me?

2) Tank position. Is there a limit on how far to go in either direction?

If it helps, I dive with an Aeris EX Lite and AL80.

 

[The Chairman]

You're asking me to diagnose a balance problem without seeing you! If you have a choice, put the trim weights on the upper cam band. Put most of your weights in the trim pouch (don't overload). You don't need much in your ditchable weight pouches if you are weighted correctly. Now try to attain trim by moving your tank forward. It's OK if you feel your reg when you pull your head all the way back. It shouldn't stop too much travel.

 

[guruboy]

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?

 

[Agathorn]

I find this interesting. A buoyancy class was always one of the first "extra" classes I had wanted to take. If you are going to be spending all that time down there, you want to do it right! Besides, one of the main things that fascinates me about diving is the feeling of flying, and being able to 100% control my body underwater is vital to that I would think. Maybe i'm just not like most people.

Unfortunately only a few months after getting OW certified, I lost my job and had to move from sunny Florida up to cold Vancouver, Canada for work. Too cold to go diving around here! And now its been over a year since I last dove So sad, I miss it.

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?

 

[gcarter]

I find this interesting. A buoyancy class was always one of the first "extra" classes I had wanted to take. If you are going to be spending all that time down there, you want to do it right! Besides, one of the main things that fascinates me about diving is the feeling of flying, and being able to 100% control my body underwater is vital to that I would think. Maybe i'm just not like most people.

Unfortunately only a few months after getting OW certified, I lost my job and had to move from sunny Florida up to cold Vancouver, Canada for work. Too cold to go diving around here! And now its been over a year since I last dove So sad, I miss it.

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?

OMG! You have no idea what you are missing! I love west coast diving!

 

[Agathorn]

OMG! You have no idea what you are missing! I love west coast diving!

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.

 

[gcarter]

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.

I've done trips to Victoria in September and May; in both cases, the water temperature was a fairly constant 6.5C - 7C (44F - 45F). 2 piece 7mm with a 5mm hood and gloves and I was toasty. Seriously, there is some really nice stuff in them there waters.

Talk to the nice folks at IDC...