Saturation Diving: The Incredible World of Underwater Construction 

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As a current saturation diver, one big correction I'd like to point out is that our saturation chambers are not submerged. Rather, they are kept on the surface but with equal pressure to the depth we are working at. We then enter a diving bell that is locked off of the system and lowered down to our working depth. Once the inside and outside pressures are equal, we can open the bottom door and exit for our 6ish hour dive. We also dive with an umbilical the feeds us our heliox, hot water, light, video and communication. It also sends our exhaled breathing gas back to the surface where the CO2 is removed, oxygen is added back in, and then sent back down to us.

I had the privilege of working in risk management for a major subsea company. Was the best and most interesting role I have done in my career, and I have done many things. Worked tirelessly over 8 years protecting and reducing risk for the divers. Never had an incident related to their safety, and that was no accident! Great content as usual!

I worked as a saturation technician in the 1990's aboard the worlds biggest dive vessel, Stadive. The dive crews spent 28 days "under pressure", 22 days working and 6 days decompressing. The crews spent most of the time at a living depth of 128 meters which equates to an O2 level of 2% and 98% helium. Best job I've done, loved it

1:05 - Chapter 1 - Ancient divers 2:35 - Chapter 2 - The 1st dive suits 4:30 - Chapter 3 - The dangers 7:40 - Mid roll ads 9:05 - Chapter 4 - Living in murket depths 13:45 - Chapter 5 - Extras

Fascinating video. One small correction, although heliox (or trimix, nitrogen, oxygen and helium) may reduce decompression times, it is primarily used to avoid nitrogen narcosis rather than the decompression sickness, keeping the partial pressure of nitrogen down to reduce the “drunk” effect mentioned at about 6:00. On dives below about 185 feet (56 meters) the oxygen content needs to be reduced below the normal 21% as well, since high partial pressures of oxygen can actually become toxic (oxygen toxicity or CNS oxygen toxicity). This is not medical advice, and all that :)

I was a SAT diver for a few years in the mid 2000s. Great job Simon the video covered the topic well.

I had a friend that welds undersea piplines around the world. He always worked over the winters in the North Atlantic and Pacific and would come home in May, buy a house and Corvette for cash, sell them in Sept and go back to work! He retired at 35 and now does real estate in Nevada

When I was a kid I wanted to be a commercial diver, I thought saturation diving was awesome. I Told my parents that, and they objected saying its not a good career and I wouldn't make much money, here I am an attorney now, and I should have just been a saturation diver and made more money than I do now :^)

I am a PADI MSDT(Master Scuba DIver Trainer) and you don't get lung injuries from descending quickly, in fact the lungs can completely compress and re-inflate on ascent during breath hold diving.

I used to work for a marine construction company. These commercial divers are a different breed. You may be getting paid $100+ an hour but you better be ready to retire by 30-35 because your body won't last.

I worked as a commercial diver for a few years. Those saturation divers really earn their pay. I'm not particularly claustrophobic, but bugger living in a decompression chamber.

As a former commercial diver, the worse part of getting bent was not the pain but rather the thoughts of not knowing if or when a N2 bubble will reach your heart or brain before you can get to a chamber. In my case it was type 1 DCS and was treated with O2 as there was no chamber in the area...I was lucky. I was within my tables and computer but the external conditions were not ideal in the north Pacific. Still the most satisfying career in my life!!

My grandmothers brother died from the bends. He was an inventor and was working on a diving helmet he would go down in the blue holes at needmore indiana where they quarry limestone. He stayed down too long and came up too fast. this was back in the 30's or 40's he was 19 when he passed. Brilliant family. Her other brothers were a doctor and a physicist.

Lets all just take a moment to appreciate Simon Whistler and his Team (of slaves). This man has taken me on a legendary journey, experiencing a plethora of wildy different subjects over an immense spectrum. I'm hugely grateful for getting these glimpses into so many unique walks of life across the modern day and throughout history. Thank You Sir Much Love 💙🖤💜🖤❤️

With a salary like that I'm guessing we'll be seeing Deep Dives with Simon Whistle popping up soon.

This is the first video in the series where I have physically been to the the places Simon is talking about. At the 7:15 mark, there is a photo of where I completed my first saturation dive. Crazy

Love your videos simon! You should do the ITER fusion reactor sometime as it's megaproject inside of a megaproject inside a bunch of other projects.

As a wristwatch aficionado I appreciate the addition of a dive watch segment. Thanks for another awesome Megaprojects video Simon!

One of my best friends, four years older than me, the guy that introduced me to Rock & Roll when I was age 10, died doing this exact type of work. I miss him greatly since it happened 15 years ago.

I'm surprised there was no mention of how Edmond Halley did a lot of work on diving bells during his life and he is one of the modern "inventors" of the bell, he really just improved upon previous recorded bell designs for commercial wreck diving.

My cousin worked as a saturation diver in the North Sea in the 1970s. He made enough money in 4 years to buy a trawler. But he has had health problems since.

As someone who has panic attacks from time to time, being a saturation diver sounds terrifying

I've been told by experienced commercial divers that there are many more new commercial divers trained every year than good jobs. Plus ROVs have displaced many saturation divers. You are a lot more likely to end up scraping boat hulls in muddy harbors for a whole lot less money than get a job doing saturation work..

There was BBC documentary film called the last breath about saturation diving, genuinely one of the most incredible things I’ve ever seen.

I dove recreationally with guys who used to do sat diving and they all said it’s definitely not a long term job as it takes a big toll on your body. 10yrs is about as much as the body and mental state can handle.

WRT sat divers, look up "aseptic bone necrosis" aka Dysbaric osteonecrosis. Also Heliox is used to reduce Oxygen toxicity at high partial pressures

I´m a NAUI Diving instructor and have done some free diving. Sat-diving scares the shyte out of me. You are locked in a cycle that is out of your control, and it is a major strain on your body. No way for me. Good video as always Simon :-)

I explored this career as a youth. It was my idea of a dream job. I'm currently a certified rescue diver,it's a certification level, not my job,but I recognize the extreme danger in the profession. Capt.Bob, SV ( Sailing Vessel) 27th Chance, Tampa Fl. It's known as off gassing. Omega seamaster 300 diver. Helium escape value. Simon, of all your channels, and I subscribe to them all,and have watched every episode. This is my most relatable. Thank you !

Love your narrative skills you know how to tell a story. Love all your works for the wealth of knowledge that they are. Many blessings and to a prosperous future

If anything this should show how adaptable humans are and how much our body’s can handle, who would have ever thought a human could submit themselves to such harsh environments and be perfectly fine. It truly is amazing what humans have done.

These divers deserve the same level of respect as astronauts.

Fascinating! Some of my favorite movies back in the day involved undersea stuff - The Abyss, and Leviathan, come to mind. Yes, they're probably very cheesy by today's standards but they were fun nonetheless, and the decompression/implosion effects were excellent. Some of the things that got talked about were 100% fantastical and went against physics too. But I've been fascinated by deep sea environments and the ways in which we can explore those environments ever since then! Also, a cousin of mine once worked on an offshore oil rig for about a decade (I think he was a roughneck). He'd spend three weeks on the rig, and one or two weeks off, but he said the dive crews had the worst, hardest, scariest job of anyone there. He also said they were all a little bit crazy which coming from THAT cousin is hilarious and a bit terrifying!!

Another excellent episode. Thankyou Mega Team.

Imagine picking up this job, thinking that you are going to make bank, only for your partner to say to you, "multiple leviathan class lifeforms detected".

Having never done saturation diving but having headied up a SCUBA program at a major University in the USA for 25 years, You did a very nice job of describing the physiology of movement thru the water column . Well done.

Much respect!!!! Y'all are amazing.

It is the uncontrolled rapid ascent that can cause lung barotrauma, if you hold your breath on the way up you might be dead by the surface. We are taught to actually punch someone in the stomach if they are panicked and bolting to the surface and holding their breath. It makes them exhale.

Awesome and informative video as always Simon. The beard is looking magnificent.

Great video idea. More dangerous jobs and activities plz Maybe an episode on the technicalities of paratroopers HALO/HAHO jumping.

Were I 40 years younger I'd give this field serious consideration. Inner-space vs outer-space, how cool.

Great video. At the beginning you go through most of the dangers that pressure / pressure changes can cause - I'd add two more that are among the most dangerous: (1) barotrauma when ascending (vs descending): risk of trapped air in say the lungs expanding quickly and damaging the surrounding tissue; and (2) oxygen poisoning - when breathing a partial pressure of oxygen > 1.4 atmospheres or so i.e. regular air at > 70 meters depth can cause rapid seizures and then death

Moonpool

Wow! Super interesting! Great job Simon and Megaprojects team!

Love this stuff!!!

My backup job is to become a saturation diver, this was really fun to watch.

Not sure if this fits as a megaproject, but i think that a video about "Live Aid" would be great. Considering how many artist performed, being broadcast to over 2 billion people all over the world.

Always love seeing my profession getting some notice. It is such a fun job the deeper you go the colder/darker it gets. Think people forget how dark it is down there. Thanks Simon!!!! Love it

Hi there - recreational Technical diver here with a couple minor corrections and additions: 1. Narcosis can be caused by any inert gas, not just Nitrogen. Modern research has actually pointed to Carbon Dioxide buildup as a greater cause for narcosis than nitrogen. 2. Helium is mixed into divers' breathing gas to lessen the effects of narcosis, not decompression sickness/obligation. Helium, being a very thin gas, has the lowest narcotic potency of any potential breathing gas by far. 3. The decompression obligation of "one day for every 30 meters" is exclusive to saturation diving. The amount of decompression obligation is a complex function of both depth and time spent at depth (as well as the gas mixtures one is breathing). Saturation diving is pushing the body's capacity to absorb inert gas into tissues to the theoretical maximum for a given depth. For example, at my certification level I can dive to 45 minutes for 30 minutes and only incur roughly a half hour of decompression obligation, with ways to shorten it if I used additional mixtures of breathing gas. It's a complex subject and probably couldn't be handled in videos with the goal as being succinct as any of Simon's channels. I've read a very dense book on the subject and there are several more out there like it. 4. Another unmentioned hazard of hydrostatic pressure is Oxygen toxicity. Breathing oxygen over a certain partial pressure (meaning it could be any percentage of the breathing gas, given a high enough ambient pressure) leads to central nervous system impact, leading to various symptoms, the most extreme of which can be seizures that can easily lead to death when dealing with the other perils of diving. As such when diving to depths below about 45 meters (so for all saturation diving needs), oxygen is actually removed from the breathing gas to the point that it would be fatally hypoxic if breathed at a regular atmospheric pressure. It remains safe to breathe due to the human body functioning not on the percentage of oxygen in the breathing gas, but rather its overall pressure in the breathing gas. Again, another very complex subject that probably is too dense to be really mentioned well in one of these types of videos.

The hospital where I used to work had a hyperbaric chamber, and I transcribed reports that described all the ways such a chamber could be used. In fact, over the 14 years I did transcription, I only transcribed one report dealing with a diver who surfaced too quickly, who came to us from the nearby Navy base. Other conditions the chamber was used for were aiding recovery from extensive burns, healing of extensive wounds in people with compromised immunity systems, aiding recovery from carbon monoxide exposure, and one unusual one I transcribed: treatment of acute onset glaucoma.

This one was pretty good Simon!

I really admire the courage and skill of sat divers. It's something I could never do (congenital issues) but I find it very interesting.

I suddenly really wanna play through Subnautica for like the 8th time.

This is so interesting, I love this topic.

In my early teens, I genuinely considered saturation diving/underwater welding as a career. Then I read about the Byford Dolphin accident. To quote a great man, “Hard no!”

Sur D 0 2, baby! You forgot Arterial Gas Embolism Simon (A.G.E). It’s also interesting that if you do get bent your more susceptible to it after that. On another note hands-down the best hangover cure I’ve ever experienced was when I was in dive school,the hyperbaric chamber it’s amazing what they do for your body. Great video man

I once held my breath in the bathtub for upwards of 15-20+ seconds, so I can relate to this video

I dive and got bent once. Spend a few hours for a couple of days in a Plexiglas tube at a hospital breathing 100% O2 at depth. Got hit in my right shoulder. Was on my 3rd deep dive and on the last dive I was drifting away for the boats anchor chain where you can not drift out to sea and do your safety stop. I had to make a run for the anchor chain fast because of strong current and to reach it had to swim up. To fast accent got me. Waited til the 2 day trip was over before heading to the hospital for treatment. OK now, no side effects.

Awesome video. I've been a technical diver (non-commercial) for over 20 years and thought about getting into saturation diving, but then I decided getting my commercial pilot licence was a better and safer idea! This video made me rethink my latter choice, but it's too late now to change. Nevertheless, I still love diving :-). Great video, as always, Simon :-).

I think living in that close of quarters with 5 other people is almost more remarkable and scary than the underwater business.

Megaproject suggestion....the Mulberry harbors....if building your own harbors and dragging them across the channel for D-day isn't mega enough i dont know what is!....lessons learnt from dieppe etc etc.

Suggestion for a megaproject / Biographic . Check out Thomas Telford . Born 15 miles from where im living , i had no idea how much this man achieved . Brdges , roads , canals , etc . He was never knighted in Britain . But he was in Sweden . Some fella . Here in Langholm , Dumfrieshire , we re more than proud of a man who changed the world

Always interesting!

Thank you for the information.

Wow that fact about the watches and Rolex at the end is crazy! Who would have ever thought the helium you are breathing would destroy your expensive watch. That is just mind blowing to me

Let's take a moment to appreciate sat divers and commercial divers they do a lot to help our civilization today❤️

Divers don't use heliox to avoid decompression illness they use it to avoid nitrogen narcosis. Helium is more dangerous than nitrogen for decompression as it is a faster gas so comes out of solution in the body tissues faster meaning more chance of bubbles.

That was cool!

Maximum respect to those that do this.

Fascinating episode.😀

My uncle did this for 15-20 years, was always terrified I wouldn't see him again.

A subject that has always fascinated & terrified me in equal proportions.

Another great video could work Simon

I would like to hear stories of weird things and events that these divers encountered while at these depths.

Fascinating topic

Thanks for the decent into this subject.

Thank you

I'd love to see more videos about dangerous careers

They deserve every cent of that 300k!!

I can’t believe I had no idea about these deep sea habitats that people live in. I always thought this was science fiction. This is the coolest thing ever.

I went to commercial dive school aback in 2010 just before the deep water horizon incident and the moratorium that happened on diving just before I got out of school. Went to Louisiana for 6 months to try and find a job and never was able to find one. A lot of companies prefer you to have some background in some type of construction, service (military, firefighter etc.) or maritime work before hiring you. If you dk t have any of that you normally have to get with smaller companies that their safety records aren’t as good and willing to take on less skilled people. Really wanted to become a sat diver would have been great. Oh well school was an amazing time and got to do things that you never would normally.

Wish the video was longer to learn my things. Maybe you could do a part 2 on this subject it's very interesting stuff. Take care and be safe. Greg

No Jacques Cousteau reference? I thought the Rolex discovery was fascinating. Maybe each mega project and side project can end with an unexpected discovery. Well done for all your great vids Simon! Casual Criminalist is amazingly engaging when you go on your tangents.

Good video 👍

Great video, but you only scratched the surface with Comex. They set the standard with their Hydra experimental dives. As far as I know they even developed breathinggasses still used today.

Simon you should have mentioned the accident on the Byford Dolphin's diving bell I know it's a bit gruesome but it's one of the biggest accidents in the field

Loved the nod to dive watches at the end. Miss the days when timepieces were valued for function over fashion.

Simon, Please cover aerial firefighters especially water bomber pilots. According to Wikipedia they can do up to 100 + takeoffs and landings under optimal conditions within a 4 hour mission while battling forest fires. Taking off and landing as you know is the most dangerous phase of flight. They have amazing flight skills and each year they lose a number of dedicated flight crews while accomplishing their high pressure tasks. Considering that fire bombing forest fires is a relatively new occupation all developed after the 2nd world war Generation 2 and 3 pilots are still refining the the skills required.

Loving the intro sounding like old school Black Sabbath

Best job I ever had

Rolex actually designed a watch that was attached to the vessel that first dove down to the bottom of the Mariana Trench in 1960 and then designed another watch to be attached to the sub that dove down there with James Cameron in 2012. Both watches survived the equivalent of over 15,000 psi of water pressure. Granted the watches didn’t have to deal with the added risk of helium changing pressure upon assent.

A commercial diver from 1977 through to 1997. Then back offshore with subsea7 in 2012. Sat with 34u chatting to the lads in the pot. I found SAT easier than basic air surface supplied. Sweating buckets in shallow gulf waters in the flash zone. Fitting a bloody great bracelet anode on vertical diagonal bracing.

They deserve every penny

There was a accident involving a chamber transfer a while back and the entire thing decompressed. And not rapidly, but instantaneously. The divers died in a very gruesome way. en.m.wikipedia.org/wiki/Byford_Dolphin

Please please do the new river gorge bridge in Fayetteville West Virginia. They jump off it annually and when it was built it was the longest and tallest arch bridge that had ever been constructed.

I loved video Simon, but one thing you said want quite right. Yes, heliox helps with dcs. But the main thing with it is, heliox almost eliminates the chance of the diver getting narked.

Nope you can get Nitrogen Narcosis at a mere 18 meters though it is rare. Most people will get it by 30 meters. Also commercial divers go to 400 meters on a regular basis in the North Sea. Comex have been working on extending that to 650 meters since 1992.

Today on Factboi News: Divers watches are hereby declared pretentious pieces of extravaganza for people with a bling fetish. Thank you Simon. Without you I would never have known! :P

Great video - I was interested in learning more about deep diving like this since I have seen The Abyss years ago, but it is a rather niche subject I found it hard to find good information.

On one hand, severe thalassophobia... on the other, this is incredibly fascinating. Mixed opinion of the field but it was certainly a cool video!