Diving Depths

[General Pain]

Well I'm doing some scuba research for my next merc mission, and I was hoping anyone could provide me with a list of :


depth - gear - acciliary gear
1 - 5m none or snorkel - none

etc

so what depth would u need an auxiliary pressure chamber or whatnot etc....after u are back on land/boat

[headquarters]

Thats a question of nitrogen saturation in the blood - and that depends on the TIME you have spent on the DEPTH as well as the DEPTH alone .

At say 2-3 meters you could probably stay under for 90 minutes without other precautions than a cold beer waiting in the boat .But as depths increase , the safe -time on the depth decreases and decrompession times increases . (The need to gradually re-surface ) .

You should go to a diving site to check this out too..

Well I'm doing some scuba research for my next merc mission, and I was hoping anyone could provide me with a list of :


depth - gear - acciliary gear
1 - 5m none or snorkel - none

etc

so what depth would u need an auxiliary pressure chamber or whatnot etc....after u are back on land/boat

[General Pain]

Thats a question of nitrogen saturation in the blood - and that depends on the TIME you have spent on the DEPTH as well as the DEPTH alone .

At say 2-3 meters you could probably stay under for 90 minutes without other precautions than a cold beer waiting in the boat .But as depths increase , the safe -time on the depth decreases and decrompession times increases . (The need to gradually re-surface ) .

You should go to a diving site to check this out too..

well it wasnt actually that I was looking for -

I was more interested in the various equipment needed forvarious depths -

[jester]

Dive phsyics has alot of stuff.

Like Time at Depth

How many other depths you have been that day, how much time topside you have in between and all of that.

As a very general rule one can stay 60 minutes at 60 feet without worry of any decompression.

Remember, for each 10m <roughly> you double the atmospheric pressure.


For gamming purposes 30 feet and under it is a long time without worry of "THE BENDS"

As for gear:

You have the following types:

Compressed air, the traditional method of diving. The standard tanks are 80 cubic feet aluiminums and 72 cubic feet steel tanks. <that is how much air they hold> How long they last varies according the persons phsycical condition, how deep they are, how hard they are working like hauling alot of gear, swimming all out or fighting a current. Each tank will last about an hour to half an hour at between 30 and 60 feet. Again a rough time limit.

Oxygen Enriched Diving or Nitrox: I am not too familiar with this system, it lasts longer and extends your bottom time and reduces your decompression I THINK. This is a mixed gas though, special equipment is needed to fill the tanks so this will not be available everywhere.

REBREATHER; WWII tech and all the highspeed SEAL stuff it is now available on the open market, it takes about 3000-5000 to purchase and that is just the system, not the tanks or other gear that is specialized to it. It uses a bottle of oxygen that is used to reconstituite the air you have already breathed into a tank that filters out the Co2. These can last about 4 to 6 hours, again depending on activity level, condition and depth.

Next:

Wet suite or dry suite so you do not get hypothermia or just end up numberand shivering when you hit the beach.

MASK and SNORKEL

Weights and weightbelt <the human body is bouyant, as is the wetsuite and air tanks, you need roughly 1 pound of led per 10 pounds of body weight> Otherwise you will have to fight to keep submerged and it really won't work to well.

FINS and BOOTIES. Some fins allow the use of regular boots, this can be stressful on the feet if swimming long distances. Or the slip on fins that do not require fins, good for warm water with nice sandy beaches, overall though, not recomended.

Scuba Tanks with a BC and Harness <Buyancy compensator, or tank pack. A Boyancy compensator is an inflatable life jacket looking thing used to stay afloat on the surface, they also have pockets for gear and a built in backpack for your tank> Or you can use the "HORSE COLAR" this is a round inflatable ring that goes around the neck like the old pilots inflatible vests, with these you need a backpack for your tank. Most tanks are carried singly, although they do have twin tank set ups, I can honestly say I have only seen them used once and I have never used them.

Dive knife; there is alot of fishing line, cordage, seaweed, kelp and netting on the bottom of the sea.

REGULATOR: this is the line that connects to the tank and goes to the mouthpiece in which you breathe from. VERY IMPORTANT! These come with at least 2 dials on them, a pressure gauge that tells you how much air is left in the tank. The second guage has a depth gauge that tells you how deep you are. It also has a needle that marks the deepest depth you have gone. Alot of them also have a 3rd dial a luminesent compass so you can do underwater land navigation which is VERY IMPORTANT since underwater visibility varies.

Flashlight; this is helpful when operating at night, or you end up with holes, caves or wrecks.

Dive Tables: this is the waterproof chart that tells you how long you can stay down and how deep after figuring the data from prior dives.

Undersuite: This is a comfort item, normaly a thin nylon type body suite you wear under your wetsuite which helps you stay warm, keeps sand out of every crevice and crack, and makes it much much easier to put on and take off your wetsuite <they are difficuilt to get on or off when wet>

Wetsuite usualy consists of: Top with long sleeves, trousers that are called OVERALLS as they resemble farmer overalls, booties prefferable with hard soles for walking on gravel and sharp coral reefs <walk on a reef barefoot and you will know!> gloves, alot of sharp shells and coral and other stuff to slice the hell out of your hands, they also burn with cold and go numb after a while. HOOD, again keeps the head warm.

That is the basic gear a diver needs, and all of this is good for about 90 feet down, of course at that depth you are looking at a bottom time of about 5 minutes if you do not want to decompress.

As for decompression chambers; they have small portable ones that are are about 30 inches in diameter and 7 feet long, they are made of a soft colapsible material. And then the ones that look like a large propane tank. However, for operations I would suggest not going to depth where you will have to spend time in a chamber, either sit tight at specific depths decompressing before hitting the surface which can be boring. Or just don't go down and stay down long enough where you have to do it, otherwise you will be wasting time that could be best spend on operations. I mean what happens if you are stuck 30 feet down waiting to decompress and an enemy boat rolls by, you will be hating life.

[Eddie]

General Pain,

Jester's list is pretty accurate. Some nitpicks could be made but nothing warranting any real corrections. Most regulators now have dive computers that erase the need for dive tables. It tracks all dive data: depth, time, date, temperature, Nitrogen loading (absorption by your body), O2 loading for NITROX computers, ascent rate, beginning and ending pressures in some models, and a plethora of other information.

For the record, if his is not substantial to answer your questions, I just received my Advanced Open Water Certification on 22 MAR, and am getting NITROX certified this weekend, and have been diving since 2002. I'm fairly knowledgeable or at the very least know the right people to ask any questions you have.

He was right about NITROX. It extends your time at depth and allows you to go deeper.

By pressure chamber, are you meaning a decompression chamber? And, what context do you mean it in? A dive emergency or we just did our planned dive and we're now mandated to go into the DECO chamber for X hours?

If the first manner, you could possibly need the chamber from an ascent from 6 feet. Likely? No. From 50 feet? Much more likely. From 90 feet? Most likely (which happened to a girl in my Advanced Open Water class).

If you mean the second situation, no recreational dive depth (up to 130 feet) will require time in a DECO chamber unless you exceed the Allowable Bottom Time (ABT). As Jester said, the ABT is significantly shorter at deeper depths.

If your mercs are using rebreathers, they can't go below 33 feet, otherwise the oxygen becomes toxic. Below 33 feet (as in 32, 31, 30, etc, not below as in 90 feet), the nitrogen accumulation in the body is negligible and a person can effectively stay as long as he has air, i.e., your tank or rebreather will stop working before it's a danger to you.

For deep diving, you have some special considerations though. At depth, because of pressure, your air in the tank is going to be smaller in volume and the air in your lungs is going to be smaller in volume. You're going to continue breathing your normal breaths though to your full lung capacity. This means you're breathing more air at the same rate you breathe less air at the surface. Your tank goes faster, in otherwords.

Also, if you want to go below 130 feet, you get into what is called Tec Diving. With Trimix gases you can go well below 130 feet. This is extremely hazardous and requires multiple decompression stops along the way up (requiring surface support stations -- essentially extra sets of gear dangling on a buoy at fixed depths), but I don't know what the threshold for chamber time is. My advice, get something reasonable sounding, like 250 feet, and start fudging something from that.

[General Pain]

I was hoping to simplify the whole ordeal into a basic shematic.

0-5meter
5-20meters
20-100 meters
100+ meters

so what equipment should/could be used at the various depths

It's no problem to divide it into more categories offcourse

but anyway thanx for the help ;)

[Eddie]

Okay, I think I understand what you're wanting. Short, simplified answer is, aside from not taking a rebreather below 1 atmosphere (10m), it doesn't really matter what gear you have.

I've seen guys dive to 100ft in board shorts and a t-shirt, and I've seen guys to 15ft in a drysuit.

I've seen skin divers go to 45 feet with just the breath in his lungs.

There is no hard and fast table like what you want besides,

0-33feet: Anything
34-130ft: Air or NITROX; no rebreathers
131-down: NITROX or TRIMIX; no rebreathers

[General Pain]

Okay, I think I understand what you're wanting. Short, simplified answer is, aside from not taking a rebreather below 1 atmosphere (10m), it doesn't really matter what gear you have.

I've seen guys dive to 100ft in board shorts and a t-shirt, and I've seen guys to 15ft in a drysuit.

I've seen skin divers go to 45 feet with just the breath in his lungs.

There is no hard and fast table like what you want besides,

0-33feet: Anything
34-130ft: Air or NITROX; no rebreathers
131-down: NITROX or TRIMIX; no rebreathers
...ok thanx....

when do you HAVE to have a "spacesuit" when the pressure is to high etc.....

basically I'm wondering what depth the next mission(s) will be......

[Eddie]

The record depth for Open Circuit Scuba is 308 meters. Note that this is equivalent to running a 4-minute mile.

It is also important to note that hardsuits are experimental items in the real world, but are designed to go deeper than 450 meters.

http://www.google.com/url?sa=U&start=8&q=http://comenius.susqu.edu/bi/320/Tech%2520%2520Diving%2520Presentation.ppt&ei=YLrVSdr0I6DItAOc6KGoCg&usg=AFQjCNEB_W9sgt0MFgX8ev4QAWQC-hv4cg

[Eddie]

Oh, the accepted range for most safe technical dives is between 130 and 350 feet, though. Your players honestly should not be going any deeper. I don't know what your campaign entails, but...

[General Pain]

Your players honestly should not be going any deeper. I don't know what your campaign entails, but...

ohh....you know.....just exploring new ways to off my players....

- shark attaks
- old ww2 sea mines
- extreme pressure
- drowning
- (combinations offcourse hehe)

- for players in my campaign...I'm just kidding ......he he he (evil grin)

[headquarters]

Firstly - the gear needed to go down to svereal hundred meters depth 200-300) is more or less the standard looking diving gear - neoprene dry suit ,mask ,leadbelt,fins ,divecomputer, ventil system /respirator etc .-and tanks .

The quality of the gear should be outstanding at anything below 50ft imho or you are liable to do yourself an injury - but plenty of perople go down with older / cheaper stuff .(Thats not to say that older is poorer ! )

Its what is in the tanks that is the main issue as fas as I know ( got the open water advanced or whatsitsname).Regular compressed air can only be used to a depth of 42 meters (?) or the oxygen will drug you and you will take your mask off to kiss the pretty fishes before you sleep a in the gently rocking current at 70 meters depth .( Or so I have heard )

When you go down below a certain depth ( I guess its roughly 60 ft) you are on a clock .The longer you stay down ,the longer you need to stop at intervalls on your way up - hanging on to an anchor rope at say 20 meters for 15 min ,then at 10 m for 10 mins etc -these depths and times are variables .

The longer you stay down ,the longer you will have to wait before you can resurface .This is because nitrogene bubbles accumulate in the blodstream ,and have to dissipate before you resurface -the nitrogene bubbles expand the closer you get to the surface as the pressure decreases.I am told it can be hurtful and cause cardiac arrest if you get into an accident with this .

Decompression chambers are used for people who go up to fast , or for people that have been down so deep and so long that they cant very well decompress in the water .

I have PM ed you a link with various dive tables that can be downloaded .

For all you divers out there -I am aware that I only know the main principles and not the details anymore ..its been a while since my last dive .

[Targan]

Firstly - the gear needed to go down to svereal hundred meters depth...
I'm pretty sure you mean feet right?

[headquarters]

I'm pretty sure you mean feet right?

I think I mean METERS - isnt the free dive record with nothing but a pair of trunks 140 meters ?

[Targan]

I think I mean METERS - isnt the free dive record with nothing but a pair of trunks 140 meters ?
Are we talking someone with a little bit of diving experience or a Navy clearance diver? If you are going down hundreds of meters you're probably going to need more than just standard dive gear - you're going to need a diving bell for decompression stops or maybe even a decompression chamber on the surface. If the diver isn't well experienced and well supported and he's going that deep I'd say there is a significant risk of death.

[headquarters]

Are we talking someone with a little bit of diving experience or a Navy clearance diver? If you are going down hundreds of meters you're probably going to need more than just standard dive gear - you're going to need a diving bell for decompression stops or maybe even a decompression chamber on the surface. If the diver isn't well experienced and well supported and he's going that deep I'd say there is a significant risk of death.


But I think that Gen Pain was asking for what ind of general diving gear you need - as fas I know its just drysuit ,flasks/tanks,fins etc -not saying that it shouldnt be of a technical quality -just that it isnt some other kindf of hardshell suit say..

As for the decompression chamber etc I totally agree .

Also - it would be a professional diver - other sshould stay close to the surface .

[Fusilier]

I'm pretty sure you mean feet right?

He probably should.

Most people can't dive deeper than 50 meters. After that it becomes a technical skill and usually requires special gases for mixing/blending. Do it wrong and you can guess what happens. In twilight 2000 I would guess making this possible (having the resources for acquiring the mixes such as helium) would be a challenge.

Only the most skilled/experienced have only really done around 150+ meters, and that requires top of the line gear and perfectly engineered trimix.

[General Pain]

http://www.impulseadventure.com/freedive/world-record.html

[headquarters]

He probably should.

Most people can't dive deeper than 50 meters. After that it becomes a technical skill and usually requires special gases for mixing/blending. Do it wrong and you can guess what happens. In twilight 2000 I would guess making this possible (having the resources for acquiring the mixes such as helium) would be a challenge.

Only the most skilled/experienced have only really done around 150+ meters, and that requires top of the line gear and perfectly engineered trimix.


Well , as I said a couple of times already - its still in principle a soft neoprene suit ,fins ,mask etc like an amateur set for PADI style recreational diving , even if the tanks are filled with trimix or helium mix and the materials ,suit regulators and masks etc have to be of a "technical quality"

So -yes I meant meters .



with technical dive gear ( 42 m + ) and gas mix .re-read the posts guys

for recreational dives , no deeper than 42 meters as far I recall ,but thats with regular compressed air in the flasks .

The questions pertain to a merc 2000 campaign run by the general -so finding gear ,getting the gas mix etc will not be a huge problem .

[General Pain]

http://en.wikipedia.org/wiki/Herbert_Nitsch

[headquarters]

http://en.wikipedia.org/wiki/Herbert_Nitsch

this isnt relevant to our upcoming mission - this is only straight down and up again , no manouvering or work done at depths.

If the mission depth is more than 50 m I guess trimix in the tanks ,technical grade diving equipment and the use of a decompression chamber is the way to go .

But as you can see - there is no need for different TYPEs of suits etc ,just a soft suit and tanks made for technical dives .

[headquarters]

http://en.wikipedia.org/wiki/Technical_diving

Also check out Nuno Gomez , he holds the world record of 318 m using scuba gear - and a variety of gas mixes to achieve such depths .

thats app 1000 feet .

Also there is a big case up here about professional diver sueing the goverment foerwhat they went through after working at depths from 70 to over 200 meters in the 1980s and 1990s.

So -that is several hundred meters -and several hundred feet as well .

[Eddie]

Also check out Nuno Gomez , he holds the world record of 318 m using scuba gear - and a variety of gas mixes to achieve such depths .


Actually, you and I were both wrong. It's Pascal Bernabe now with a record of 330 meters.

"Bernabe broke the record in Corsica on open circuit scuba, with a descent time of less than ten minutes and a total time of 529 minutes for decompression.

The world record dive was the 41-year-old's fifth attempt at breaking the open circuit deep diving record, which he spent three years preparing for. Dive manufacturer Ralf Tech sponsored the event, which involved a dive support team of thirty team members and 12 support divers.

The experienced deep diver completed the dive on trimix, carrying a total of seven cylinders. In addition, 20 cylinders of various gas blends were also placed on three decompression lines."

Note that no diving bell was needed, no decompression chamber after the event, nothing special except for the 27 cylinders and 12 support divers, which are the surface support station equivalents from my original deep diving post above.

[jester]

So, yes your character can dive deep and hide out at depth as long as he is willing to sit out the decompression time and of course has the tanks staged.

OR, he can skip the entire step, if he has a boat waiting on the surface and he jumps right into a decompression chamber as soon as he hits the surface. That could reduce the need for staged gear and speed up the entire operation rather than him waiting underwater and holding up the mission.

And now for ways to bring harm to your players,


Well, Claustaphobia! either underwater, in the mask or inside the decompression chamber which leads to panic.

Gear malfunction: This can be anything from a leaking mask, to a bad gauge that tells him he is deeper or shallower than he is, a bad chronometer or dive watch, or a bad tank gauge telling him he is out of air when he isn't or has air when he hasn't.

Lost fin- a pain in the ass.

Lost or cracked mask

Lost weightbelt-

shifting gear or weightbelt

Can't get the right bouyancy so he is always fighting a bit to keep from sinking or from floating

Lost flashlight, knife or other small piece of gear

Broken zipper on wet suite, or worse a dry suite.

Ear Squeeze <where the pressure on the inner ear does not equalize> these are very painful

Ruptured eardrum, even more painful

diving with a sinus or ear or similiar condition- pain and misery

Pulled muscle- always get them.

Cut on coral, line or gear

Tangled in coral or line or gear straps

Faulty regulator- this is your airsupply

Faulty O ring on the tank, which makes it leak.

Valve on your tank is not turned on, or get bumped and turned off.

Wrong WetSuite for the conditions or time underwater which can be uncomforatable to deadly,

Bad air or gas. This happens even today. This can make one ill or dead.

Oxygen poisoning, where it gets toxic

Nitrogen Narcosis- or divers high, where the nitrogen levels are altered and you get drugged effect, this can be anywhere from just feeling good to wanting to swim to the seafloor and full on halucinations,

The Bends; you come up to fast nitrogen bubbles in your system increase and it can cause headaches, paralysis that can be permiment, blood vessels rupture, even a brain embalism which gives you the effects of a stroke or even death.

Ruptured lung: going up to fast without exhauling which causes lungs to burst. <Do not hold your breath when you surface!!!!>

Rupture Ear Drums, again pressure injury.

Other equipment failures, a malfunction bouyancy compensator after a dive not the time to fight to stay on the surface and in position after an exahusting dive.

Firegrass! I hate you guys in OZ for importing your seaweeds here! Its in my marina now and I got some last time i dove to work on my boat, stings like a mo fo!

Jelly Fish these are more common that sharks

Sharks sure

Agressive sea animals like sea lions, or seals or just curious ones who will get in your way or mess with your gear.

Dolphines you see a large gray fish shaped thing underwater and it gives a fear factor.

EELS these are more dangerous and common than sharks

Octopus and Squid, some can be agressive

Coral, it will shred you nicely

Panic

Getting Lost

Waves and Surf these will mess you up.

Boats, they can hit you, or you can surface under them.

Tunnels and Wrecks, getting lost, trapped or falling items or what not that can fall on your or cut you.

Fishing line, fish nets and seaweed or kelp forests all a danger for getting tangled.

Submerged logs, pier pillings and other debris, in a tidal area these are dangerous.

Missing your boat, a navigation issue, but remember that movie Openwater?

Anyhow, those are some of the things off the top of my head.

Oh you can have the evil villian have trained seals, sea lions and dolphins not with lazers attatched to their heads, but that patrol the underwater area with cameras or even a form of handcuff or legcuff <they had them on mailcall or some such show> or just counter divers hunting your characrer.

I hope this in some small way helps make your characters lives all the shorter and a bit more misrable.

[Targan]

The questions pertain to a merc 2000 campaign run by the general -so finding gear ,getting the gas mix etc will not be a huge problem .
Well that will teach me for not reading the first post in a thread more carefully. I understand now. My apologies.

[Targan]

Note that no diving bell was needed, no decompression chamber after the event, nothing special except for the 27 cylinders and 12 support divers, which are the surface support station equivalents from my original deep diving post above.
I see your point but this sounds like a guy whose entire life probably revolves around diving and it took three years of preparation for that one attempt. For a Merc:2000 mission you're probably going to have personnel who have a slightly broader skills set at the expense of extreme niche specialisation. And your average Merc:2000 mission is more likely to have a prep time of three weeks than three years. On the other hand a sufficiently well connected, cashed up Merc team could certainly seek to recruit elite standard divers and support personnel.

[General Pain]

So, yes your character can dive deep and hide out at depth as long as he is willing to sit out the decompression time and of course has the tanks staged.

OR, he can skip the entire step, if he has a boat waiting on the surface and he jumps right into a decompression chamber as soon as he hits the surface. That could reduce the need for staged gear and speed up the entire operation rather than him waiting underwater and holding up the mission.

And now for ways to bring harm to your players,


Well, Claustaphobia! either underwater, in the mask or inside the decompression chamber which leads to panic.

Gear malfunction: This can be anything from a leaking mask, to a bad gauge that tells him he is deeper or shallower than he is, a bad chronometer or dive watch, or a bad tank gauge telling him he is out of air when he isn't or has air when he hasn't.

Lost fin- a pain in the ass.

Lost or cracked mask

Lost weightbelt-

shifting gear or weightbelt

Can't get the right bouyancy so he is always fighting a bit to keep from sinking or from floating

Lost flashlight, knife or other small piece of gear

Broken zipper on wet suite, or worse a dry suite.

Ear Squeeze <where the pressure on the inner ear does not equalize> these are very painful

Ruptured eardrum, even more painful

diving with a sinus or ear or similiar condition- pain and misery

Pulled muscle- always get them.

Cut on coral, line or gear

Tangled in coral or line or gear straps

Faulty regulator- this is your airsupply

Faulty O ring on the tank, which makes it leak.

Valve on your tank is not turned on, or get bumped and turned off.

Wrong WetSuite for the conditions or time underwater which can be uncomforatable to deadly,

Bad air or gas. This happens even today. This can make one ill or dead.

Oxygen poisoning, where it gets toxic

Nitrogen Narcosis- or divers high, where the nitrogen levels are altered and you get drugged effect, this can be anywhere from just feeling good to wanting to swim to the seafloor and full on halucinations,

The Bends; you come up to fast nitrogen bubbles in your system increase and it can cause headaches, paralysis that can be permiment, blood vessels rupture, even a brain embalism which gives you the effects of a stroke or even death.

Ruptured lung: going up to fast without exhauling which causes lungs to burst. <Do not hold your breath when you surface!!!!>

Rupture Ear Drums, again pressure injury.

Other equipment failures, a malfunction bouyancy compensator after a dive not the time to fight to stay on the surface and in position after an exahusting dive.

Firegrass! I hate you guys in OZ for importing your seaweeds here! Its in my marina now and I got some last time i dove to work on my boat, stings like a mo fo!

Jelly Fish these are more common that sharks

Sharks sure

Agressive sea animals like sea lions, or seals or just curious ones who will get in your way or mess with your gear.

Dolphines you see a large gray fish shaped thing underwater and it gives a fear factor.

EELS these are more dangerous and common than sharks

Octopus and Squid, some can be agressive

Coral, it will shred you nicely

Panic

Getting Lost

Waves and Surf these will mess you up.

Boats, they can hit you, or you can surface under them.

Tunnels and Wrecks, getting lost, trapped or falling items or what not that can fall on your or cut you.

Fishing line, fish nets and seaweed or kelp forests all a danger for getting tangled.

Submerged logs, pier pillings and other debris, in a tidal area these are dangerous.

Missing your boat, a navigation issue, but remember that movie Openwater?

Anyhow, those are some of the things off the top of my head.

Oh you can have the evil villian have trained seals, sea lions and dolphins not with lazers attatched to their heads, but that patrol the underwater area with cameras or even a form of handcuff or legcuff <they had them on mailcall or some such show> or just counter divers hunting your characrer.

I hope this in some small way helps make your characters lives all the shorter and a bit more misrable.
priceless list here,,,,,,,thanx alot

[Targan]

I just occurred to me, if you bought/hired/stole a small rescue or research submarine (the kind with omni directional impeller thrusters, remote manipulator arms, high end sonar/magnetometer/inertial guidance/multispectrum camera s/ULF radio electronic gear, docking cuffs and air locks) you might be able to remove the requirement for individual deep diving. Or make things much safer and easier for the divers if they were still required.

Imagine how satisfying it would be to raid a NUMA facility, execute that hyper-macho narcisist Dirk Pitt when he refuses to surrender control of his ship and steam off into the open ocean under cover of darkness in the finest Horn of Africa traditions of piracy.

[headquarters]

Well that will teach me for not reading the first post in a thread more carefully. I understand now. My apologies.
your Australian - you are supposed to behave like that ;)

[headquarters]

I see your point but this sounds like a guy whose entire life probably revolves around diving and it took three years of preparation for that one attempt. For a Merc:2000 mission you're probably going to have personnel who have a slightly broader skills set at the expense of extreme niche specialisation. And your average Merc:2000 mission is more likely to have a prep time of three weeks than three years. On the other hand a sufficiently well connected, cashed up Merc team could certainly seek to recruit elite standard divers and support personnel.

it will be your usual ramshackle operation that ends in a fervent display of ungallant gunplay before we speed of -probably leaving a team member down there to decompress with whats left in his tanks before he has to resurface to where the enemy as anchored ...

no PCs are "tecnical divers" as far as I know -2-4 points I guess .Should make the average rolls quite interesting at 150 meters depths..

hehe..

better bring a back up PC

[Eddie]

I see your point but this sounds like a guy whose entire life probably revolves around diving and it took three years of preparation for that one attempt. For a Merc:2000 mission you're probably going to have personnel who have a slightly broader skills set at the expense of extreme niche specialisation. And your average Merc:2000 mission is more likely to have a prep time of three weeks than three years. On the other hand a sufficiently well connected, cashed up Merc team could certainly seek to recruit elite standard divers and support personnel.

True, but the need for decompression chambers and special equipment and skills was negated by the 529 minute ascent. That achieved the same effect of coming out, going to a chamber, and sitting there for 529 minutes. That was the point that I wanted to make with that paragraph, that there are ways of doing the same thing without needing massive pieces of equipment like a DECO chamber.

Will players want to do that (or logistically be able to)? Not likely without handwaving of passage of time from the GM. Maybe a good time for a diving skill check and a panic check in whatever respective system you use for your game, then move on to the next scene.

Another thing, physical preparation for diving doesn't require a lot, especially ascending and descending along reference lines. Running is sufficient for most diving as that will affect your breathing and your endurance. Flutter kicks are used to improve your kick cycles. Nothing else is really needed.

[jester]

Things to remember for diving:

Lung Capacity, the better and more effecient your breathing is and body is in conditioning the longer your air will last and the more control over your breathing you will have.

Legs, how in chape they are? When I don't dive for months or years or when I was having surgeries every year or so <like now> I could expect some severe cramps in the legs while diving. I work through them, but over the years they are felt more and more when I do dive. These can be dangerous and can eve put a person out of action.

HYDRATION!!! If diving with compressed air, it is dry air, and your mouth will become dry, you will be doing some serious exercise and because you are in a water enviroment you won't feel it as much as say a desert, but you will become dehydrated.

And down right fatigue; again diving is some massivily intense work, and it will wear you out. Fighting to swim, fighting to breathe and fighting and taking a bashing from the currents and waves. And the cold. This will all sap your strength.

Cold; even in a wetsuite it does take its toll. And without gloves, a hood or a wetsuite it will be felt more, and it can cause hypothermia. As well as making you number and feeling more fatigued.

Not wearing gloves? You will get some nasty slashes, handling gear or buckles can even cause some slashes to your fingers if you have been underwater for sometime. And CORAL <can't say it enough> or muscle shells. I sliced the hell out of my hands a few months ago simply pulling up a line on my boat that had falled into the water a few weeks prior. Muscles had started growing and as I pulled the line in, it ran through my hand and sliced the thumb and part of the palm. They are hard and they can be sharp. Same goes for barnacles.

Those are some additional dangers and worries to consider.

[Eddie]

I love Hawaii. Water temperature 71 degrees at 103 feet. We had guys diving in board shorts and t-shirts.

[Targan]

Not a world record, but topical.

With one single breath, 92 metres down, Walter Steyn smashed the Australian free-diving record.

In just two minutes and 43 seconds, the 36-year-old this week extended his own record to retain the title.

Steyn previously held the record at 77 metres and last year won second place at the world championships for Dynamic no fins at 175 metres.

"I've always known I could dive deeper but in the past I've had equalisation problems that have often made me turn too soon," Steyn said.

"I'm absolutely stoked."

Setting the new Australian record during Vertical Blue 2009 at Dean's Blue Hole in the Bahamas, Steyn said the dive turned out to be easier than he expected.

"I got the tag from the bottom plate," he said.

Steyn's record-breaking efforts have been filmed on location by the under water film production company BlueEyeFX, which will document the invitational free-diving competition.

[Rupert Willies]

Not a world record, but topical.

Some disciplines of free diving:
* Static apnea is a competition discipline which is just what it's name implies. Holding ones breath for as long as possible under water motionless ( the world record is over 10 minutes).
* Constant Weight Involves swimming vertically down a shot line to achieve a maximum depth and returning to to surface with the same amount of Weight that one has used to get down.
* Free immersion is similar but no fins are allowed.
* NO LIMITS is perhaps the most spectacular. Fans of the Movie the Big Blue will be familiar with the images of breath hold divers plummeting into the depths hanging on to a metal sledge The world record currently stands at over 150 meters!!
* Dynamic apnea is a horizontal distance attempt.

[Rupert Willies]

Diving minutes


Depth m: Equipment: Cost: Comment:
0-5
Nothing / goggles
Free
Most people that can swim can do this. Alignment not critical


5 - 10
mask/fins/snorkel
$50 - 175
Must align pressure, some training required


0 - 18
Tank/regulator/octo/guages/compass/buoyancy compensator/mask/snorkel/fins/knife/suit/weights
$350 - 3000
Basic training required to avoid pressure sickness, like PADI OWD or similar. Suit can be anything from nothing to heavy drysuit. If dry suit, then more weights and more training is needed


0 - 30
Like above + torch/diving computer/gloves
$650 -
Colder water deeper down, lower visibillity. If longer dives at depth exeeding 25m, safety stops should be practiced. Requires more training


- 75
Like above + 2xtanks mix gas/dry suit/extra tank for suit/pony bottle/
$
Insulating gas for suit, extra tank with breathing mix (one down, one up), breathing gas is mix - Nitrox, Heliox or Tri-mix. Below 66 metres Oxygen is toxic, diving below this depth requires comprehensive training. Requires decompression


- 75
Like above / rebreather/
$4000 -
Requires separate training for the rebreather. Requires decompression


75- 200
Surface supplied diving/hardtop/
$10000 -
Professional/military diving. Must have team at surface, support vehicle


50- 500
Saturation diving
$50000 -
Professional diving. Saturation diving allows divers to live and work at depths lower than 50 m for weeks at a time. Requires hyperbaric chamber/diving bell, and living and working chambers. Usual 'travel rate' is 15 m per day, so to be desaturated from 150 m takes 10 days.


below 500m
Liquid breathing
$ ???
Experimental diving technique, requiring extensive education, and massive support teams. Diver breathes oxygen enriched liquids. Requires mechanical ventilator to aid the diver in ventilating the lungs at a great enough rate to expell CO2

[General Pain]

Diving minutes


Depth m: Equipment: Cost: Comment:
0-5
Nothing / goggles
Free
Most people that can swim can do this. Alignment not critical


5 - 10
mask/fins/snorkel
$50 - 175
Must align pressure, some training required


0 - 18
Tank/regulator/octo/guages/compass/buoyancy compensator/mask/snorkel/fins/knife/suit/weights
$350 - 3000
Basic training required to avoid pressure sickness, like PADI OWD or similar. Suit can be anything from nothing to heavy drysuit. If dry suit, then more weights and more training is needed


0 - 30
Like above + torch/diving computer/gloves
$650 -
Colder water deeper down, lower visibillity. If longer dives at depth exeeding 25m, safety stops should be practiced. Requires more training


- 75
Like above + 2xtanks mix gas/dry suit/extra tank for suit/pony bottle/
$
Insulating gas for suit, extra tank with breathing mix (one down, one up), breathing gas is mix - Nitrox, Heliox or Tri-mix. Below 66 metres Oxygen is toxic, diving below this depth requires comprehensive training. Requires decompression


- 75
Like above / rebreather/
$4000 -
Requires separate training for the rebreather. Requires decompression


75- 200
Surface supplied diving/hardtop/
$10000 -
Professional/military diving. Must have team at surface, support vehicle


50- 500
Saturation diving
$50000 -
Professional diving. Saturation diving allows divers to live and work at depths lower than 50 m for weeks at a time. Requires hyperbaric chamber/diving bell, and living and working chambers. Usual 'travel rate' is 15 m per day, so to be desaturated from 150 m takes 10 days.


below 500m
Liquid breathing
$ ???
Experimental diving technique, requiring extensive education, and massive support teams. Diver breathes oxygen enriched liquids. Requires mechanical ventilator to aid the diver in ventilating the lungs at a great enough rate to expell CO2

this was exactly what I was looking for ;)

Can't wait till the end of May.....underwater firefights at 100m below the surface with - the russian underwater gun perhaps? (SPP1)
http://thebigbookofwar.50megs.com/DOX/Guns/Special%20Guns/

[Rupert Willies]

I did send you this two weeks ago...

[General Pain]

I did send you this two weeks ago...

I prefer posting this here than on one of my many email addresses......:D

(I usually don't pay attention to the hordes of mail I get every day...)