New Tech Kit

[Mark Chase]

Originally Posted by nigelH

I read that report too and wondered why.

I doubt it was his wing size that was the problem but if a report ever materialises, and they rarely do, we will see. He was a well liked moderator on RBW so I prefer not to speculate.

His wing isn't relevant one assumes it wasn't working. If you have ever tried to get off the bottom deep with the standard wing for a Classic when wearing three full bailout stages you would know what I mien, its a bit squeaky. Add another diver and another three stages and you stand little or no chance.

What exactly happened is not relevant either. The fact is they didn't have enough lift to lift available to lift him.

Many will tell of being bearly able to keep their mouths above water with the standard inspo wings and heavy stages. I binned the standard Classic wing as inadequate and opted for the 66lb lift Custom Divers TDB

I have never felt over dressed


ATB

Mark

[Fiona]

Anyway back to Air Guzzlers questions

I think we can safely say and unusually all agree the OMS comfort harness is rubbish and far from comfortable.

[Mark Chase]

Originally Posted by ianfirmin

Nigel is probably correct but does not explain why. Human bodies are close to neutrally buoyant. A large body is surrounded by a large buoyant suit (wet or dry) that needs more weight to maintain neutral buoyancy. However, and I'm guessing here, I wouldn't expect the difference to be much more than 6kg between the typical small person and the typical very large person.

What you need adjustable buoyancy for is the weight of gas you are carrying. To be able to use all of the gas in your cylinders you need to be neutrally buoyant with empty tanks. Thus, with full tanks, you need extra buoyancy at the start of the dive. Using rough figures for air, your 12l tank at 232bar contains 3.3kg of air. Thus, when you start your dive (perfectly weighted) you need 3.3kg of buoyancy to maintain trim. At another extreme, you may have a triplet of 20 litre tanks and a couple of 12 litre stages. This amount of gas weighs 23.4kg. Now, say you are the careful type and would like to ensure you have sufficient buoyancy in the case of a drysuit flood you might need another 6kg of buoyancy. Thus, total buoyancy requirement is in the region of 30kg (66 lbs).

Now. There could be the case that you are carrying so much kit, wrecking bars, tools, torch batteries etc that you are negatively buoyant at zero bar gas without any extra weight. You need to add this to your buoyancy requirement. Even so, I must admit that a 90lb lift wing seems overkill for virtually any "normal" dive.

One corollary of this is a refutation of the concept of just using a drysuit for buoyancy adjustments. Even a single 15l of air has a potential buoyancy change of over 4kg. I would hate to dive with an extra 4 litres of air in my drysuit.

One final point. All the figures above relate to air and the same volume of helium weighs a lot less.

ATB
Ian

The maths is simple for boyancy control but for emergancy lifts and for keeping you comfortably out of the water you need a lot more than enough wing for boyancy control.

I used a 35lb lift wing on my Inspo with two 7ltr stages and it just isnt enough lift on the surface. I dive a 5mm semi compressed dry bag with 200g Thinsualte and carry no lead at all but my Counterlung case does weigh 4kg so arguably I carry 4kg of weight a normal divers rig wouldent have.

Its not just me, a lot of inspo divers find the standard wing inadiquate.

ATB

Mark

[Mark Chase]

Originally Posted by Fiona

Anyway back to Air Guzzlers questions

I think we can safely say and unusually all agree the OMS comfort harness is rubbish and far from comfortable.

Definitly

ATB

Mark

[Woz]

I've got a 45lb wing and it provides loads of lift with steel twins and ally stages.

Now OMS have got a couple of things very right with their wings:
1. Camband slots. Had to Stanley knife some into my Frog. Bloody SA crap.
2. Eyelets around the inside of the bladder.

Now. What significance, says you, do the eyelets round the middle of the bladder have? Well here's a thing. Instead of using them for the intended bungees, you can "lace" them up in a shoelace pattern to the spare holes where your cylinder studs go through. Hey presto! A single tank wing without bungees.



Ignore the bungees on that photo. That's not what we want to do. We want to narrow the middle of the horseshoe bit so the wing doesn't wrap around the single cylinder.

[Mark Chase]

Originally Posted by Woz

.

I am also a big fan of the lift being all down the bottom of the wing. It realy lifts you up out of the water.


Custom divers wins hands down on cam band slots. It has six across the back to alow mounting of a single tank or twin indi 12s with just a couple of cam bands.

Red Sea instant twinset.

[Woz]

And the OMS version of a Red Sea instant twinset. No Buddy Blocks required. Just the right shape backplate.



Any wing that has any buoyancy that sits higher than your mouth has it in the wrong place. As you sit vertically in the water at the surface, any of the wing sitting out of the water isn't providing any lift. The OMS wings are just the right shape to put virtually all of the buoyancy below the water, where it's needed.

I say Mark who is that handsome chap in the black wetsuit? It can't be the Dud. He looks almost stylish and colour coordinated.

[nigelH]

Originally Posted by Mark Chase

Its not just me, a lot of inspo divers find the standard wing inadiquate.

That's why we tend to use the 22Kg wing option for tech diving.

But then a lot of Inspo divers hold their heads in their hands and wail that OTS counterlungs don't leave them with a clear chest and their credibility as a technical diver is in ruins. Then they hang two great big bailout stages in front.

[Air Guzzler]

Thanks guys for the advice just 1 question about my BCD that i use at the moment

If you can dive with twin 12's and around 25 kg of lift would my T52 Hover

T52 - Hover BCD

be suitable to start with

[Paul Oliver]

Originally Posted by Fiona

Anyway back to Air Guzzlers questions

I think we can safely say and unusually all agree the OMS comfort harness is rubbish and far from comfortable.

Yup