In defence of being vertical...

[jrtonkin]

Reading through the thread about how many diver's do and don't suck, a frequent comment was made about being vertical in the water as a bad thing.

Before I get completely defensive, and start claiming that for some people a horizontal hover is impossible, I'd like to hear people's suggestions on how I might be able to achieve this...

The problem basically comes down to I've got "cyclist's physique"... I.e. big legs, big lungs, and very low overall body fat. So my legs sink and my torso floats, though not enough to overcome my legs; wearing only a bathing-suit I'm still between neutral and a pound or so negative on a very full breath of air.

Unfortunately, this body-shape also puts my center-of-gravity down around the top of my pelvis... Quite a ways below where my center-of-buoyancy is, and also below where a BC's waist-belt would wrap around my body.

Thinking about the physics of it, it should be possible to use a high-mounted tank-weight to control this, but that has two issues. First, I'm still at the rental-phase of things, so I'm not sure how I'd go about rigging a removeable tank-weight.

Second, since the entire BC and any tank-weights are going to be above my CoG, it looks like I'd essentially have to end up hanging from the waist-belt, while the tank-weight forced my shoulders down enough to balance the torque of my legs... Which just doesn't sound comfortable. (Now this is just a guess, based on thinking about the forces involved, I havn't tried it, and if someone with a similar default-vertical-orientation has and it's not as bad as it sounds, I'd like to hear about it)

So, anybody marketing ankle-floats? That or butt-mounted bouyancy...

Jamie

 

[otter-cat]

I've often wondered if there were such things, as I am very top-buoyant (bottom-heavy) myself. I can hold myself horizontal in the water, but it takes a lot of muscle work, and is therefore energy-consuming. I've never seen any ankle floats marketed, but let us know if you find some!

One thing that may help is getting more weight higher up on your body, by using a steel backplate/wings set-up, or buying a bcd that has weight pockets higher up. I know seaquest has (or had) at least one model of bcd that had a couple of pockets for putting a few pounds of non-ditchable weight near the shoulder blades.

 

[Scubaroo]

Positively buoyant fins might help as well.

 

[ckharlan66]

I have a buddy that puts his weight belt under his underarms to move the weight up and help him get horizontal. This can also be solved with a back plate or by using tank weights.

Good luck.

Chad

 

[O-ring]

You can counter this with steel tanks, a stainless steel BP, adding a v-weight or a weighted STA, or using trim weights or tank neck weights.

 

[TwoBitTxn]

The issues are:

Divers being verticle at or near the bottom and reducing visibility.

This is solved in part by being aware there is a problem and doing your best not to be the cause of it. You can be horizontal and still accomplish the same thing. (Rototilling)

Rental gear: It depends a whole lot on what it is you are renting. If you can rent soemthing with trim pouches put a portion of your weight there. There are tube weights that will wrap around your tank valve. These work well too. The point is to get a goodly portion of your weight forward and move your center of gravity forward.

When it comes to buying your own gear consider some of the previous recommendations.

Best wishes,

TwoBit

 

[MikeS]

You can wrap ankle weights around the tank valve and remove an equal amount of weight from your weight belt.

Mike

 

[Caffiend]

jrtonkin once bubbled...
Before I get completely defensive, and start claiming that for some people a horizontal hover is impossible, I'd like to hear people's suggestions on how I might be able to achieve this...

The problem basically comes down to I've got "cyclist's physique"... I.e. big legs, big lungs, and very low overall body fat. So my legs sink and my torso floats,

Hey, I was in this same spot just over a week ago. I've got the same physique. Between stance work in Kung Fu and mountain biking, I'm all leg. I had already made the switch to a back-plate and wings (Halcyon) but still was having problems. I then started addressing my weight. I hadn't readjusted after shucking the vest BC from OW class yet and after spending a few minutes with the BP/W I shed all my weight from my waist; this is with an AL80 tank. This was a tremendous help. I didn't need any more mass down low.

Then came DIR-F... I had picked up a couple of cam strap trim pockets to play with. After DIR-F, I returned them. After getting my back plate actually properly positioned and working on technique I realized that trim pockets were just a crutch for improper form (in my case, not to say they aren't useful for some). It's all about arching the back and pulling the legs up and back.

I don't know if you're diving in a full suit and booties, but getting a few mils of neoprene on your legs definitely won't hurt.

-will

 

[100days-a-year]

I mount bladder on the highest set of grommets or if only one set use a grommet maker to put them higher.This puts the air bubble closer to my c.o.g.This is one of the 1st things any advanced class should teach...how to set up gear properly instead of encouraging all sorts of crutches to offset poor gear set-up and poor technique.The angry looks you get when you're the cause of a siltout are good indicators of needed changes.Ask the guys who noticed and ask them how to improve .Someone who doesn't know why it's bad can't be expected to know how.