How can it be done

[Lincoln_Rhyme]

I was searching on the internet for stuff to inspire me and came across this photo. what do i need to be able to create something like it?

I only want replies from people who have the experience and knowledge, know what they are talking about.  this means a certain 8 legged creature that's been acting like a jerk is excluded.  that means this

 

 

 

[ALwin]

30 minutes ago, Quibiss said:

A flooded cave and diving equipment?

Yep.  You need:

• Scuba diving training
• Cave diving training
• At least several dozen dives worth of experience, no less than 100 dives
• Very good control of trim and buoyancy
• An underwater photography setup

[Lolucoca]

Cave diving is the most dangerous sort of diving since you can't just go up and breathe again. You need to have a lot of experience for that. 

[ALwin]

6 minutes ago, Lolucoca said:

Cave diving is the most dangerous sort of diving since you can't just go up and breathe again. You need to have a lot of experience for that. 

I wouldn't recommend cave diving training without at least 200 logged dives.  Because IT IS dangerous.

[Lincoln_Rhyme]

18 minutes ago, Lolucoca said:

Cave diving is the most dangerous sort of diving since you can't just go up and breathe again. You need to have a lot of experience for that. 

 

18 minutes ago, ALwin said:

Yep.  You need:

• Scuba diving training
• Cave diving training
• At least several dozen dives worth of experience, no less than 100 dives
• Very good control of trim and buoyancy
• An underwater photography setup

so i can't just train as a scuba diver and do this and why is cave diving dangerous?

[ALwin]

14 minutes ago, Lincoln_Rhyme said:

 

so i can't just train as a scuba diver and do this and why is cave diving dangerous?

No you can't.  Normal scuba diving is done in open water, where the surface is always accessible to the diver.  Cave diving falls under the category of recreational TECHNICAL diving if not pure TECHNICAL diving.

 

In recreational diving, in day time you can dive into a cavern and go a maximum distance of 20 meters inside or maybe less (if I remember the regulations correctly).  The entrance of the cavern must also be visible above water.  If you go beyond that distance or dive the same cavern at night (because the entrance is no longer clearly visible) it is treated as a cave dive.  As a pure recreational diver, there may be some guided very easy beginner level cavern and cave dive tours you might be able to do, but the caves used for these dives will be very easy beginner level ones.  Even then, there will be regulations governing what sort of training and experience you need to have to go on such a guided dive.

 

If you want to do proper underwater photography in a cave dive, you need to be a certified cave diver with experience.

 

As for why cave diving is one of the most dangerous sports in the world:

• If something goes wrong during a dive, you cannot exit easily and help can not reach you easily. 
• 99.99% of the time if you suffer an accident in a cave dive, you could lose your life.
• And you're using specialized diving gear setups, which you need to be trained for.

That's why cave diving requires specialized training, experience, confidence, and staying level headed if you ever encounter a dire situation.

[Lincoln_Rhyme]

4 minutes ago, ALwin said:

snip

thanks ALwin.  I see in your signature that you are a scuba diver and underwater explorer. what sort of training do you have and do you also do underwater photos and how do i start training to be a diver?

[ALwin]

3 minutes ago, Lincoln_Rhyme said:

thanks ALwin.  I see in your signature that you are a scuba diver and underwater explorer. what sort of training do you have and do you also do underwater photos and how do i start training to be a diver?

I'm a Swiss Federation/CMAS 2** diver and I sometimes do underwater photography and video using either my GoPro, Nikon D800E or Canon G16 in Ikelite housings.

 

Training to become a scuba diver, you can start out easily with PADI Open Water and Advanced Open Water certification.  This will qualify you to dive down to a depth of approximately 30 meters under water.  But if you want to train as an underwater photographer, I recommend you also take TDI Intro to Tech (which I have taken) or GUE Fundementals courses and have at least 100 logged dives outside of the dives you do for the courses, and at least 50 or so dives after the TDI/GUE courses.  I also suggest you take a recreational Nitrox diving course.

 

You can also think about whether you want to use an open circuit or closed circuit setup, in which if you go for a closed circuit setup you need another specialized training on learning how to use a Rebreather (closed circuit).  With regular scuba gear, which is open circuit, the air you breathe out is exhausted into the water and form loud noisy bubbles.  This can scare away any marine life you are trying to get close to for a photograph.  This is where a closed circuit Rebreather comes in handy because you don't exhale any air into the water.  No bubbles are formed, at least not ones large or noisy enough, to scare away the fish.

 

For cave diving, which I am not certified to do, both TDI (Technical Diving International) and GUE (Global Underwater Explorers), offers very good training.

[Lincoln_Rhyme]

ok what are the different level of dive training?

what is nitrox?  sounds like something from Fast and Furious

what are the different gear setups, you mentioned specialized gear?

whats the difference between tdi and gue?

[ALwin]

29 minutes ago, Lincoln_Rhyme said:

snip

OK different levels of dive training quality you to:

• be certified to dive down to certain depths (recreational diving limits you to a max depth of 40m, any deeper and you need technical diving training which I will explain later)
• use different types of gas mixes (which includes Air, Nitrox also known as Enriched Air, and Trimix which involves breathing Helium)

In PADI you have (keep in mind I am only covering the generic levels):

• PADI Open Water which teaches you the basics of diving and qualifies you to dive down to a depth of around 18 meters.  This is similar to the level of Swiss Federation/CMAS 1* (pronounced 1 Star)
• PADI Advanced Open Water which teaches you the basics of five specialty skills (most of them just covering things at an introduction level), and qualifies you to a depth of around 30 meters.
• PADI Deep Diver Speciality qualifies you to a max depth of 40 meters.  Swiss Federation/CMAS 2** also qualifies you to 40m.  Swiss Fed/CMAS doesn't have something equivalent to PADI AOW.
• In PADI, after that there are courses like Rescue Diver (which only qualifies you to assist a diver who is having trouble, you cannot use this certification to work as a police/fire department/public services rescue diver).
• PADI Dive Master which you can only do after completing the Rescue Diver course, qualifies you to work as a dive tour guide or an assistant to an instructor.  Swiss Fed/CMAS 3** is this level.
• To be an instructor you need to be certified as an instructor.
• Other training agencies like SSI, TDI, GUE, etc. have their own recreational and technical diving courses separated into different levels.

This was for recreational diving.  For the Technical Diving side:

• I won't cover the PADI ones because I think the way PADI has structured the courses is primarily to make money.  Basically they charge you money to be qualified for every 5 meters deeper you want to go after 40m.
• With agencies like TDI and GUE, they are simple:
  • Tech 1 (sometimes spelled Tec 1) which qualifies you to dive down to 60 meters.
  • Tech/Tec 2 which qualifies you to dive down to any depth beyond 60 meters that your instructor takes you.  Only limited by the risks you're willing to take.
  • Cave 1 and Cave 2, which share a similar idea to Tec1 and Tec 2.
  • of course in order to even take Tec 1 or Cave 1 you need to have taken prerequisite courses like Intro to Tec/Fundies, Advanced Nitrox and Decompression Dive courses.

 

For example, Swiss Fed/CMAS for recreational diving (Rec) is:

1. CMAS 1* (open water diver)
2. CMAS 2** (40 meter max certified diver)
3. CMAS 3*** (Dive Master equivalent)
4. CMAS 4**** (very advanced diver, but you don't need 4**** to become an instructor)
5. CMAS M1 (first level instructor, can teach CMAS 1* I think)
6. CMAS M2 (second level instructor, can teach up to CMAS 3***)
7. CMAS M3 (country director, course director, the highest level of CMAS in a country)

 

FYI, if you're wondering why I am not a Dive Master, there is a good reason.  The moment you become a CMAS 3*** level or PADI Dive Master, you start to become liable.  Even if you're not teaching a course or you're not working as a guide, even if you're with a friend and diving for fun, if something happens to your dive buddy you can be liable (at least in countries like France and Switzerland where I've dived).

 

Nitrox means a mixture of Oxygen and Nitrogen where the Oxygen content is higher than normal, enriched air.  The air we breath normally consists of approximately 21% Oxygen, 78% Nitrogen and about 1% of other gases.  Contrary to popular misconceptions that some people have, scuba divers do NOT breathe a tank of just Oxygen (they can, which I will explain the circumstances for it later).  Nitrox is a mixture where the percentage of Oxygen is increased into the gas mix to reduce the risks of Nitrogen Narcosis when diving.  In diving, Nitrox is divided into two levels:

• EAN 40% (where Oxygen can be mixed into the gas up to 40%), you can learn this as a recreational diver.
• Advanced Nitrox (where the Oxygen mixture can go as high as 100%) which is one of the prerequisite courses for technical diving training.

Nitrogen Narcosis is the effect of the Nitrogen in the gas on the body as you breathe the pressurized gas.  It sort of makes you feel dizzy, like you're drunk.  While every diver will be narc'd, different people experience it differently.  In all my years of diving, I don't think I have ever noticed it, perhaps because I have a high degree of mental focus or concentration.

 

With each increase in the percentage of Oxygen in the gas mix, the shallower you have to stay.  Because the risks of Oxygen Toxicity becomes higher with increased O2 in the gas and with depth.  In recreational diving, the standard Nitrox mixes you'll find at dive shops all over the world are 32% and 36% O2 mixes which limit you to going to a max depth of about 34 meters and 29 meters respectively.  If you are using a tank of 100% O2, the recommendation is no more than 6 meters deep.  Again these are general recommendations based on studies of dozens to hundreds of divers.  Again, like Nitrogen Narcosis, different individuals have different risk factors with Oxygen Toxicity.

 

To be continued in another comment...

[ALwin]

The basic setup for recreational divers consists of:

• masks, fins, exposure protection suit (wet suit or drysuit), perhaps gloves
• dive computer or tables, compass
• buoyancy control jacket or wing
• scuba regulator set in the form of at least one first stage, two second stage regulators (one primary, one backup), a pressure gauge, and an inflation hose for the buoyancy control device
• and of course a tank of gas (normally regular mix of air under pressure, at least 200 bar)
• if you dive in cold water, you need two sets of regulators:
  • primary first stage with primary regulator and the low pressure inflation hose for the buoyancy control device
  • secondary first stage with secondary regulator , gauge, and if you use a drysuit then a hose for drysuit inflation (or you use a pony bottle for the drysuit, which can sometimes be filled with Argon gas if you're trained for such a setup)
• In recreational setups, the secondary regulator is often colored Yellow and called the Octopus.  You use it if your primary regulator fails or if your buddy needs to breathe from your tank.
• In a Hogarthian setup, the primary regulator is attached via long hose that is also looped slug around your body.  If your buddy needs to breath from your tank, you need to give the long hose to him. Your secondary regulator (your backup reg) is on a short hose and attached to your neck with a bungee cord.
• the Hogarthian setup also uses a backplate and wing system instead of a jacket like BCD.

Basic recreational regulator setup which may be used on a single scuba tank that has a single valve or a dual valve.

 

Cold water recreational setup, which will require a single tank with a dual valve system or a twin tank system.

(I can't find a image for this, but it's basically using the recreational hose setups with dual first stage setup of the Hogarthian system.)

 

And the Hogarthian system which requires a long hose/short hose combination and if you're using a twin tank, you need a manifold valve setup for the twins which is the valve in the middle.

 

These are all open circuit setups.  For closed circuit (there is such a thing as semi-closed but I won't get into that), also known as Rebreathers, you are basically wearing on your back a system that recycles the air that you exhale.  So the tanks of gases in a rebreather may be smaller and carry less gas, because the air you exhale is scrubbed of the CO2 you breathe out, you can breathe the O2 that you didn't consume again.  That's why open circuit systems require larger tanks, because every time you breathe out O2 that your body hasn't consumed is being released into the water and being wasted.  But rebreather systems are more complex and require more training and care.  Unlike an open circuit system if something fails you can switch to a backup regulator or tank or share air with a buddy, if a rebreather fails you can't switch to a backup regulator attached to the same rebreather.  You need to switch to a spare tank of air you will have to carry.

 

 

 

As for the basic difference between TDI and GUI, it's how they teach people to use gas mixes.  GUE originated as an agency that concentrated on exploratory cave dives where the problem is you don't always know the depths you'll be going in the cave system.  So unlike TDI which teaches students to prepare the right gas mix for the dive they are planning, GUE teaches students to use standardized gas mixes which covers various ranges of depths which might not be optimal for the actual depth you are diving.  For example, say you are planning to dive down to a depth of 80 meters (the current world record is 332.25 meters on open circuit):

• GUE will teach you to use a standard gas mix that might cover a depth range of 75m - 90m
• TDI will teach you to prepare a gas mix that is optimal for that 80m dive.

I hope I've managed to answer your questions in brief.  There's so much to cover and basically if you really want to know more, take scuba diving courses.

[Lincoln_Rhyme]

wow you know so much, thanks for sharing. so much stuff to absorb

[ALwin]

4 hours ago, Lincoln_Rhyme said:

wow you know so much, thanks for sharing. so much stuff to absorb

You're better off taking the courses.  Too much stuff for me to explain on a forum like this without going into dozens of posts.

 

If you want to become a simple underwater photographer, get certified at this level, have at least 100 logged dives in open water:

• Advanced Open Water / Deep Diver certification down to 40m (or CMAS 2**)
• Recreational Nitrox certification
• Work on your trim and buoyancy which you can learn from a proper instructor that teaches actual trim and buoyancy instead of that fin pivot or Buddha stance nonsense.

[Lincoln_Rhyme]

1 hour ago, ALwin said:

You're better off taking the courses.  Too much stuff for me to explain on a forum like this without going into dozens of posts.

 

If you want to become a simple underwater photographer, get certified at this level, have at least 100 logged dives in open water:

• Advanced Open Water / Deep Diver certification down to 40m (or CMAS 2**)
• Recreational Nitrox certification
• Work on your trim and buoyancy which you can learn from a proper instructor that teaches actual trim and buoyancy instead of that fin pivot or Buddha stance nonsense.

ok but i don't know if i will really take scuba diving courses yet, i'm not a good swimmer.  by the way ALwin you mentioned recreational and technical diving a few times, what is technical diving? and whats the difference between a wetsuit and drysuit and i've heard of semi-dry suits?

 

[ALwin]

22 minutes ago, Lincoln_Rhyme said:

ok but i don't know if i will really take scuba diving courses yet, i'm not a good swimmer.  by the way ALwin you mentioned recreational and technical diving a few times, what is technical diving?

Yeah, you should practice your swimming if you want to be a diver though it's not really as important as you might think.

 

Recreational diving:

1. max depth 40m
2. max O2 percentage in a gas mix is 40%, no trimix
3. no deco dives
4. no stage tanks

Technical diving (in the sports and recreational sense, not the technical diving that commercial divers who work underwater as a profession)

1. can be both no deco and decompression dives
2. trained to use a gas mix of up to 100% O2 and as low as 1% O2 mix, with various combination of Nitrogen and Helium gas mixtures
3. can be certified to dive to any depth beyond 40m, though beyond 60-80m is considered taking chances at your own peril
4. can use as many stage tanks as necessary
5. must know decompression procedures
6. must be able to calculate a dive plan on paper and be trained to dive only with a depth gauge and bottom timer without the use of a dive computer

In both senses, you cannot get the certification and work as a commercial diver in any industry.  The only job with this level of training you can do is either as a dive guide for tourists and instructor to teach other recreational/sports technical divers.

 

You can use this table here as a guide

https://en.wikipedia.org/wiki/Technical_diving#Scope

 

Wetsuits, semi-dry and drysuits are all exposure protection suits for diving.

• Wetsuits and semi-dry are both actually wetsuits.  The semi-dry has better wrist and ankle sealing to reduce the circulation of water between outside the suit and the thin layer of water between the suit and the skin.  Both are usually made of neoprene materials and comes in thickness of 3mm to 7mm.  Some cold water semi-dry suits add another vest like layer for the torso, at least doubling the layer.
• Wetsuits and semi-dry suits keep the diver warm and comfortable during a dive with the suit's thickness and by retaining a thin layer of water between the suit and the skin, where that thin layer of water is heated by the human body.
• The suit, because it is made out of neoprene, also gives the diver a bit of extra buoyancy, however with depth the suit compresses so that buoyancy effect gets lower with increasing depth.
• Drysuits, as the name indicates, keeps a person completely dry (at least from neck to the feet).  They can be made of neoprene, trilam, and kevlar materials.  They have rubber, silicon or neoprene seals around the neck and wrists to prevent water from coming in.  Drysuit divers need to add an additional inflation hose to their regulators or use a small pony bottle to fill the suit with air or argon.
• Drysuits are more suitable for diving in cold water than wet/semi-dry suits.  Cold water divers wear thermal underwear and sweater like drysuit undergarments to increase the warmth and comfort.  Unlike wet/semi-dry suits, the materials of the drysuit does not keep the diver warm because they tend to be thin.  My trilam suits from Waterproof and Bare are very thin.  The human body heats up the air that's trapped in the suit and that air also acts as an insulator.  The air cannot (and should not) be able to circulate or leak out of the suit during a dive.
• Air must be added into the drysuit with increasing depth to prevent the suit from squeezing the body, and when ascending the air must be slowly purged off.  Drysuits come with a purge valve and it's usually placed on the upper left arm. 
• Like wet/semi-dry suits, drysuits can also provide additional buoyancy, even better than wet/semi-dry suits because the drysuit is inflated with air.

I started learning how to dive with a semi-dry suit because I trained in the cold lakes of Geneva.  But later I got a drysuit and I haven't switched back, even in warm water.  Easier to put on and take off, more comfortable underwater, easier to control buoyancy.

 

Drysuit inflate valves are usually at the chest area and the purge valve is somewhere around the upper part of the left arm.

 

[Riley-NZL]

The water in that shot is very clear, in most ocean water you won't be able to see that far clearly.

 

Gear wise, you'll want and fullframe DSLR, and widish angle lens, a dive housing (these are very expensive, and require a lot of maintenance to keep working well). Lastly is underwater lights, light does not travel very far underwater (unless in exceptionally clear water).

 

If you are shooting near the surface, an fullframe DSLR isn't as much of a deal, but deeper down you will want the high ISO performance of an fullframe sensor.