Holding depth in Water column??

[Charlie99]

If there aren't any floaties in the water, then in most cases you will either be either 1) close enough to the surface that you can see it and use the surface to judge depth, or 2) you will be deep enough that you should be able to easily control your depth by looking at your depth gauge now and then.

When just hanging out horizontally doing an ascent, I have found that the feel of water movement, when combined with feedback from ears, gives me enough clues to reasonably control my ascent with eyes closed. That doesn't help much though in your situation where you are swimming. Doing some eyes-closed ascents, though, is really good training on controlling your buoyancy. Try it at your next safety stop --- gradually get used to keeping your eyes closed for longer and longer periods and seeing if you can stay at your chosen depth.

I have also found that what type of kick one uses has an effect on the ease of buoyancy control. A frog kick or any other kick with long glide cycles gives you a period where being off neutral buoyancy will cause you to sink or rise, thereby giving you feedback. A continuous flutter kick OTOH will tend to mask the fact that you are not neutrally buoyant.

 

[don Francisco]

However, there is probably enough debris in the water if you look carefully. Even in the Mexican cenotes I found more than enough floaties to hold depth when needed.

Yes, floating matter is a good reference for checking vertical drift, but slight amounts of drift can add up over time, so my analog gauge is the final arbiter in low vis situations.

 

[hudson]

I don't get much feedback from my ears that'd be of any help with regards to staying within a few feet of depth.

*Frog kicking is probably essential for this, as Charlie pointed out.
*You need to have both a depth gauge and compass on your wrists, both in your FOV at all times
*Keep your regular breath relatively shallow, not so much to minimize buoyancy changes but more so you have enough space in your lungs to add or subtract buoyancy when needed. The moment you see >1ft of change in your depth, stop finning and initiate breath control to get your depth back in control. You shouldn't have to fiddle with your BC.
*If you are fairly stable depth-wise when not kicking, you may have a trim/attitude issue, Correct accordingly.

 

[Thalassamania]

Frog kicking is probably essential for this, as Charlie pointed out. - Not really essential, a flutter kick with a long glide is fine too, it's that GLIDE that's important.

You need to have both a depth gauge and compass on your wrists, both in your FOV at all times - yes, good to have them on the same hand. A watch with a depth alarm can be helpful too.

Keep your regular breath relatively shallow ... you shouldn't have to fiddle with your BC. - Yes.

If you are fairly stable depth-wise when not kicking, you may have a trim/attitude issue, Correct accordingly. - Yes.

 

[wreckchick]

SLOW DOWN!!!

Yes, I said it out loud. The biggest thing I see is that people doing nav skills race through them. Watch the depth and the compass but take a nice long breath between kicks so that you're not zooming a little up or a little down which can add up over just a few kicks if you're cooking.

YMMV.

Rachel

 

[kidspot]

When I dive Molokini crater (Maui) where the vis can be 250 ft I can still see little "floaties". Not many, and when someone first told me to watch them I told them there were none, but sure enough there are little things in the water that remain amazingly still (you only need one in sight, not lots of them) We will do free ascents where the bottom is 250ft - 400ft deep and often out of sight, very little in the water column, but I just look for that one thing floating there.

Next make sure your depth gauge is on your wrist where it is easily kept in sight.

Establish a stable breathing pattern and watch the "floaty" and your gauge. The things in the water will give immediate feedback on where you are heading, and the gauge will let you know if that object starts moving up or down in the water column requiring you to pick a new "floaty" to watch.

If you are doing an ascent launch a DSMB at the beginning of your ascent so you have a point of reference - I have knots tied at 10ft intervals on my line to make this simpler. It will bounce up and down with the wave action, but it will give you a visual reference point to watch.

Finally, do not base your depth off your buddy - but do pay attention to them. So many times I have watched my buddy as a visual cue, not realizing they were doing the same ... neither would notice it until a big change in depth had ocurred (8-12 ft).

Just a few things I've done to help myself with blue water bouyancy issues - and I'll probably still find them challenging after 1000 dives, but so worthwhile.

Aloha, Tim

 

[fisheater]

Very timely thread for me. Thanks everyone for some good ideas.

I did a BUNCH of dives this weekend, earning my PPB, UW Nav, Deep and Night certs. As my UW Nav. classmate was, shall we say, navigationally challenged, we NEVER got back to the anchor when she was leading. Hence, I did my first and many other free ascents without any reference line. I managed to hold my position at my SS for the first half, at least, then I'd either drift down a bit or find myself at the surface.

It's certainly a difficult skill to master, especially in a 7 mil FJ. Mine, at least, really changes in buoyancy between 20 and 15 feet.

 

[medic001918]

Very timely thread for me. Thanks everyone for some good ideas.

I did a BUNCH of dives this weekend, earning my PPB, UW Nav, Deep and Night certs. As my UW Nav. classmate was, shall we say, navigationally challenged, we NEVER got back to the anchor when she was leading. Hence, I did my first and many other free ascents without any reference line. I managed to hold my position at my SS for the first half, at least, then I'd either drift down a bit or find myself at the surface.

It's certainly a difficult skill to master, especially in a 7 mil FJ. Mine, at least, really changes in buoyancy between 20 and 15 feet.

Congratulations on your continued education. The last 30 ft of any dive is where you generally see the largest change in buoyancy. This has to do with the fact that it's the greatest atmospheric change while diving. When you descend to 33 ft, you're doubling the pressure (going from 1 ATA to 2 ATA). When you continue to 66 ft, you're only seeing less of an increase (going from 2 ATA to 3 ATA), adding another 33% to the picture. As you reach 99 ft, you have a smaller change yet of only 25% (3 ATA to 4 ATA). Most people have the hardest time with buoyancy near the surface for this reason. Any small thing has a larger impact on you...a larger breath, not venting your BC or drysuit, wetsuit compression, etc.

Shane