Preperation for a deep dive...

[J1M1]

im going to offer some advice. I would get some training for deco and some training for mix. Commercial is very different and follows different protocols for emergencies and such. I would dive to the level i am trained at. Even though you have commercial experiance, that may not be suited for deeper recreational dives. You could get hurt bad or worse. Remember that you are the one making the gas switches also and that you are in control of your decompression profile, no one else. A likely bottom time with open circuit is going to be (a long dive) 30 min for this depth. Get a few years experiance before you dive it..Don't want to be the guy that is the butthole but you can get killed fairly easily on a dive to 210 where the task loading is going to be heavy..Good luck however you decide to handle this. Hope the decision is responsible either way....JD

 

[Scubamedicjoe]

Ok I been reading this I have this to say: first this is most defiantly a trimix dive
Second are you trying to commit t suicide, have you ever been on air craft carrier if not then your in for a big surprise.
At the very least I would get cave and wreck cert first.
I believe they are going to seal allot of the entrances, but could be wrong I now they have a team of navy divers that will diving it within few days of sinking to inspect everything ECT.
This dive is very very dangerous as there are many problems i.e. Gas consumption if you Don’t have idea what your consumption is all ready your in trouble before you hardly get started. Second getting loss, which will be allot easier than you think even with ropes.
And temp exposure would highly recommend dry suits
I would really rethink this if I were you.

 

[theskull]

running a reel, etc... worse case senerio with the reel, I have to haul it in to find out where I've been.

NOPE!

Worst case scenario with the reel, you are hundreds of feet in when you discover that the line snagged and broke a couple hundred feet ago, and when you turn to try to feel your way out you get tangled in that last hundred feet of loose birdnested line, then while struggling to get free you cut through a regulator hose on a sharp piece of metal doorway . . . etc, etc, etc.

You have not even begun to think through the actual hazards of this dive.

Dive safe . . . within the limits of your training and ability,
theskull

 

[junior diver]

I'm 14, I have very little knowledge of technical diving, no, re-phrase that, NO knowledge of technical diving. But if you have dived to 282 on air as stated in your profile I am sure that you are able to plan a dive to 210 on mixed gas.

 

[Seabear70]

It's not that simple.

You see most of my past diving experience to these depths has been as a commercial diver. Which though some of the basic skill are the same, is a very different thing. For example, your rate of assent is controlled from the surface, which can bee good and it can be bad, but it is deffinately different. Another prime example is that in scuba, you if you need to be repressurized, it may take hours to get to a chamber, in commercial diving, it's part of the dive plan.

Now, one of the problems I am having planning this dive is that I am approaching it like a commercial diver, but instead of surface decompression I plan on doing in-water deco. Which as has been pointed out would require an enormous ammount of air.

As for the people who are asking if I'm trying to find an interesting way to commit suicide, the Joke's not the least bit funny. Do a search on fatalities on this board. There are pleanty. But to most people the risks associated with diving are purly academic. I have a slightly different view. I once almost drowned in 8 feet of water, I've taken a massive CO2 hit. I had a friend freak out in 260 ft of water and pull of his hat, he didn't make it. I know a Navy Seal who decided to to try to see how long he could hold his breath. He drowned in 3 feet of water. He did live, but he will never dive again. I've seen a man burn out his lungs due to an O2 hit. He'll never dive again. The theoretical risks involed in diving are very real to me, they were a fact of life for years.

Now, will I do this dive? Maybe, if I can figure out all the specifics of what needs to be done to do it safely.

As for the guy who complained that I did not know specifically how much air I would consume at that depth. I can give you a good estimate. I will not be using an estimate if I do this. I will first find out exactly how deep I need to go, and then perform test dives to the nessecarry depth and do an actual measure of my air consumption. From there I will know how much gas I need, and I will then figure in a good amount of surplus.

If this dive is done, and I say if, I will be absolutely certain that I can do it. Part of the preperation will be getting additional training, part of it will be a whole lot of diving.

 

[junior diver]

Oh, sorry. I didn't realise there was a difference between doing it commercially and setting up your own team. My comments are with-drawn and I've just realised how stupid I sound but I'm goin to post this anyway. It's like I said, "I have NO knowledge of technical diving." And in the early posts, thanks for the Navy Manual. Very interesting reading.

 

[Seabear70]

Don't feel bad, I started this thread as much to get people's input as I did to get people thinking and talking about doing stuff like this. There is a big difference, and you know that now, though the specifics are probably still a little vague to you.

 

[Jason B]

I will first find out exactly how deep I need to go, and then perform test dives to the nessecarry depth and do an actual measure of my air consumption. From there I will know how much gas I need, and I will then figure in a good amount of surplus.

these are the comments that say "I'm not yet ready".
Read this.
http://www.scubadiving.com/training...d/calculating_scr_(surface_consumption_rate)/

 

[Seabear70]

Great, so that gies me an estimate to start with to use on my test dives? And yes, I know that formula even if it has ben years since I had to use it. I do not like estimates based on assumptions, for example, it would be colder at depth, how exactly is that going to affect you gas consumption? I would be performing a hard dive, swimming for as much as a half hour non-stop that will have an effect.

At this point I am not going to say for certain that this dive will happen, there are a couple of things I am trying to workout, but so far, the only thing I have manged to draw off of this thread is to consider the possibility of weather.

Once again, let me state this plainly, I will not do this dive if I cannot work out a safe dive plan, and if I am not convinced that I can carry it out safely. At this point I do not have the plan, and I am not convinced that I can carry it out safely. I will be working toward both. What I would appreciate is, instead of shooting down a guy's dream, take the time to point me in the right directions to make it happen.

 

[Matthew]

these are the comments that say "I'm not yet ready".
Read this.
http://www.scubadiving.com/training/specialty_and_advanced/calculating_scr_%28surface_consumption_rate%29/

Seabear himself realizes that he's not ready, but I'm sure he knows how to compute his SAC.
However I dont think that "Thirty-three feet for 10 minutes ......Kick out five minutes and back five minutes at roughly your normal dive pace" will give a good indication of gas consumption for such a level of work and task loading as when diving a wreck below 200 ft. while carrying/managing multiple tanks and other equipment.