What do you call this gear?

[MXGratefulDiver]

Nothing? Somebody should explain that to these guys:

NEDEG - North East Diving Equipment Group Homepage

... maybe you should contemplate for a moment what SCUBA stands for. Here's a hint ... it doesn't stand for "surface supplied"..

When was the last time you saw somebody diving in Cozumel or the Caymens in the rig you posted in the original post of this thread?

Get serious. If you want to dive that rig, great ... but walking around on the bottom in lead boots isn't recreational scuba diving ...

... Bob (Grateful Diver)

 

[descent]

Akimbo, as always, thanks so much for your insight.

On the subject of using a nose block, perhaps in a huge hurry ...



... do you expect that this fellow will be using his hat for flotation near the surface briefly, or will he just plummet to the bottom like a stone?

 

[Akimbo]

... do you expect that this fellow will be using his hat for flotation near the surface briefly, or will he just plummet to the bottom like a stone?

Hard to tell. Some guys can equalize as fast as the tender can feed out umbilical. He may also have the nose-block already pushed in and exhaling through his nose to equalize. He may also be in very shallow water since he isn't wearing a bailout.

It "looks" like he has too much weight to be neutral, which you would expect without fins.

Edit: A modern lightweight hat like this is virtually neutral so you can comfortably work in any position, so no buoyancy unlike Heavy Gear.

 

[descent]

... A modern lightweight hat like this is virtually neutral so you can comfortably work in any position, so no buoyancy unlike Heavy Gear.

Neutral? I did not know that.

I would donate money, time, and transportation to help start something like NEDEG on the West Coast. Learning and diving the new gear would be a real treat.

 

[Akimbo]

…I would donate money, time, and transportation to help start something like NEDEG on the West Coast. Learning and diving the new gear would be a real treat…

I have always gained insight from diving new gear. You “might” be able to arrange a demo dive for a group at a commercial diving school like Santa Barbara City College, National University Polytechnic in San Diego, or Divers Institute of Technology in Seattle.

Another interesting and fun option is to arrange chamber rides. You have one close by in Pacific Grove that has recently been refurbished. You can perceive a great deal in a chamber that goes un-noticed in the water as well as safely experiencing Nitrogen Narcosis well beyond most diver’s training.

Hyperbaric chamber reopens in Pacific Grove

 

[scjoe]

... maybe you should contemplate for a moment what SCUBA stands for. Here's a hint ... it doesn't stand for "surface supplied"..

When was the last time you saw somebody diving in Cozumel or the Caymens in the rig you posted in the original post of this thread?

Get serious. If you want to dive that rig, great ... but walking around on the bottom in lead boots isn't recreational scuba diving ...

... Bob (Grateful Diver)

It may not be "SCUBA," but it can be recreational diving.

 

[MXGratefulDiver]

It may not be "SCUBA," but it can be recreational diving.

... in a boutique sort of way, and in very limited environs. I don't think anyone wants to see hordes of divers tromping around the reefs in that kind of gear ... it might work for a week or two, till the reefs got so trashed they wouldn't be worth seeing anymore.

That equipment was designed for workers who have to spend many hours at a time underwater ... not traveling vacationers with limited training and experience. Of course, just like some people who believe that cave diving or free diving equipment is the optimal solution for "any environment" ... so do some hardhat divers seem to believe that their gear of choice is the "best" for everyone. The reality is it's the best choice for the application it was designed for, and while it can be applied in a broader sense, that application comes with some drawbacks that have to be considered on a case-by-case basis ...

... Bob (Grateful Diver)

 

[Akimbo]

It occurred to me that I should complete the equalizing discussion. Most divers including commercial use the Valsalva maneuver to equalize, but that’s not the only option. Many commercial and freedivers have learned alternate equalizing techniques that don’t require blocking the nostrils, though for different reasons. However, these alternate techniques are very useful to recreational divers as well — if you are lucky enough to be physiologically compatible and dive often enough to master one. For example, photographers descending anchor lines in a current run out of hands for equalizing. That is behind the statement “Some guys can equalize as fast as the tender can feed out umbilical” in Post #53.

Freedivers run out of the lung volume necessary for the diaphragm to press air into the Eustachian tube around 20M/66'/3 ATA so must master another method to dive deeper. Freedivers also descent in the 50M or 200’/minute range. Surface-supplied commercial divers are often limited by decompression time so getting to the bottom/work site quickly is very important since the bottom-time clock starts when they leave the surface.

The nose-block mechanism in modern lightweight masks and hats made by Kirby Morgan has already been explained. Many of the earlier lightweight hats and the deep sea hat like in the original post don’t have nose blocks. Primitive as it sounds, the diver would press their upper lip against a protrusion inside the hat to block the nostrils. You can move your head around inside the old deep sea gear and move the hat a little in lightweight models using a neck dam.

 

[Superlyte27]

The gear in the OP was developed by Augustus Siebe in the 1830s. Air continuously flowed, there was no demand regulator though some divers had tried jury-rigging one into a hat in the late 1950s and early 60s. To my knowledge, the classic spun-copper free-flow helmet and attached drysuit (or "dress") has never been used except for surfaced-supplied diving.

Saturation diving was developed by the US Navy’s Captain George Bond (affectionately known as Papa Topside) in the 1960s. All divers know that the deeper we go and longer we stay, the longer decompression will be. That is true until we stay long enough for our tissues to become fully saturated, as they are normally as sea level. At that point decompression times no longer increase. Theoretical saturation time is about 24 hours. As a result, it does not matter if you stay 24 hours, 24 days, or 24 months, the decompression time is the same. Typical sats are 2-4 weeks on the bottom (plus decompression) or until the job is done. Many jobs last much longer so crews are swapped out through various chambers connected to the complex.

You hear about some habitat-based scientific saturation dives but they are relatively shallow and rare. Sat crews live in chambers on deck pressurized to their holding depth, typically at the shallow range of their working depth. They transfer to the work site via a diving bell, lock out, and typically spend 6-12 hours between crew changes. They all wear lightweight hats and hot water suits breathing HeO2 mixtures typically between .3 to .8 ATA O2, almost always using a closed-circuit surface-based recirculating system to conserve gas.

Search Saturation Diving on YouTube, there are lots of videos. I never realized that people might confuse the oldest diving gear (after breath-holding) with the most advanced and sophisticated diving. Here is an image of a typical North Sea saturation diving support vessel.

View attachment 134830

She is 94 Meters long x 18 Meters wide, supports 18 divers in sat to 370 Meters (1,214 FSW) with two bells and a ROV (Remotely Operated Vehicle). Onboard gas is measured in hundreds of thousands of cubic feet.

Ahhh! You should have posted Chet Morrison's Sat vessel, complete with fireball and dead crew as they tried to cut into a charged natural gas pipeline.

---------- Post added March 4th, 2015 at 02:21 PM ----------

To get back to equalizing..... and a tender paying out umbilical: Real World Scenario (Sometimes)

It wasn't uncommon to jump off a pier, boat, oil rig. It also wasn't uncommon for the tender to throw the entire pile of umbilical in the water... so you dropped as fast as gravity would pull you. But that's okay, later in the dive, when it's time to ascend, the tender was going to pull you to the surface literally as fast as they possibly could. Exhale hard, hope you don't get an AGE. Thankfully you'd be in the chamber in under 5 minutes anyway.

I was always fortunate. I never had a problem equalizing. The only method I've ever used was the nose brace on the various KM hats. Or if you were in a Swindell or Desco, you could fit your fingers into the neck dam. But always the Valsalva. You get used to it. I miss my Superlite 27. I don't miss the work.

 

[scjoe]

... in a boutique sort of way, and in very limited environs. I don't think anyone wants to see hordes of divers tromping around the reefs in that kind of gear ... it might work for a week or two, till the reefs got so trashed they wouldn't be worth seeing anymore.

That equipment was designed for workers who have to spend many hours at a time underwater ... not traveling vacationers with limited training and experience. Of course, just like some people who believe that cave diving or free diving equipment is the optimal solution for "any environment" ... so do some hardhat divers seem to believe that their gear of choice is the "best" for everyone. The reality is it's the best choice for the application it was designed for, and while it can be applied in a broader sense, that application comes with some drawbacks that have to be considered on a case-by-case basis ...

... Bob (Grateful Diver)

I wasn't aware anyone was promoting it for Caribbean reef dives or as a replacement for scuba gear.