Preperation for a deep dive...

[Seabear70]

Hi everybody, I'm fairly new to this board, but as I've seen it there are some very good divers here, and I am curently working on a deep dive plan that I would like some input on. I'm not really certain where this belongs on these boards, but this looks like a place to start.

I figure that I'll probably be making this dive next summer, and so I'll be using this as a sort of training log, and a place to critique what I'm planning.

Much of my experience is in commercial diving, so a lot of what I decide will be heavily slanted toward the skils I've picked up in that line of work. This will be the first time I've tried to real convert everything I've learned in those years over to scuba and put it on paper, or pixel as the case may be.

As I see it there are five aspects to a deep dive involving inwater decompression...

1. Mental, emotional comfort in the dive, familiarity with equipment, dedication to the training and dive, etc...

2. Physical, developing the skills and the level of physical fitness nessecary to complete the dive safely.

3. Equipment, chosing and learning to use the proper equipment for the dive.

4. Planning, the dive, supplies, support, etc...

5. The dive itself. This is just a part of the process, and to see it as the end is probably dangerous.

I will be updating this periodically, and later tonight I will start by outlining the first aspect, Mental.

Thanks for your patience, if people think this is stupid, I'll stop it.

SeaBear

 

[partridge]

Yes, there are a lot of very good and experienced divers in this board. I'm not one of them but am just curious, how deep is deep?

 

[Seabear70]

Roughly 210' with a current estimate of a bottom time of one hour.

Basicly I want to do a penetration and survey of the Oriskany. I cannot yet say where I will be entering and exiting, as I intend to try to aquire the plans and read others observations of the ship before attempting the dive. The environment will play a huge part in my decisions as to how to do the dive, and if I can proceede.

Basicly I'm not going to go into this blind or alone. I intend to have a solid plan worked out before making any attempt at this dive, and I am hoping to assemble a team of likewise adventurous souls to accompany me.

My decisions as to why to dive this ship are simple. One, because of it's recent sinking, read that as not sunk quite yet from what I understand, mean that the structure should be relatively stable and free of debris. The depth, while deep is not outrageous. The size of the wreck is large enough to present some interesting photo ops. And it's relative closeness to shore and probable attractiveness to divers mean that if an emergency should take place, there wil likely be a large number of people in the area to assist.

That, and diving a flattop sounds really cool.

 

[Knavey]

Roughly 210' with a current estimate of a bottom time of one hour.

Basicly I want to do a penetration and survey of the Oriskany. I cannot yet say where I will be entering and exiting, as I intend to try to aquire the plans and read others observations of the ship before attempting the dive. The environment will play a huge part in my decisions as to how to do the dive, and if I can proceede.

Basicly I'm not going to go into this blind or alone. I intend to have a solid plan worked out before making any attempt at this dive, and I am hoping to assemble a team of likewise adventurous souls to accompany me.

My decisions as to why to dive this ship are simple. One, because of it's recent sinking, read that as not sunk quite yet from what I understand, mean that the structure should be relatively stable and free of debris. The depth, while deep is not outrageous. The size of the wreck is large enough to present some interesting photo ops. And it's relative closeness to shore and probable attractiveness to divers mean that if an emergency should take place, there wil likely be a large number of people in the area to assist.

That, and diving a flattop sounds really cool.

Ever been on an aircraft carrier before? One that is right side up, and tied to a pier? Trust me, you go in one door, down a flight of stairs, and you could wander a week and never find your way back out.

I am not a wreck or tech diver. Your profile looks like you have a lot more experience than I do...but your post sounds a bit iffy to me.

I would encourage you to approach that wreck with caution...It's going to be clean - yes. It's going to be crowded - yes. But if you turn the wrong way below decks on a ship that size, and they aren't going to find you for weeks. Maps really won't help you much. Sailors paint everything grey. We even had address stencilled on the walls so you had an idea where you were at. Every room looks like every other room on the ship. Some are just bigger than others.

I'll give you an example of the confusion that can happen. Nimitz class aircraft carrier. You only have 2 decks that have passages that run the entire length of the ship. Every other deck is filled with dead ends, and passages that connect with stairs to go to other decks that have passages that connect with rooms that have stairs that connect with another deck that has a room that has a stair that goes to...nowhere! Get the picture?

Example...Lets start in the office for a department called RC-41. You walked out of the "office" into a small storeroom. You climbed a ladder into one of the catapult rooms. Go through that room, to a door that led to a passage that goes down 2 flights of stairs. At the bottom of that stairway was a doorway that went through the bulkhead (this was one of the armored bulkheads) and right back up another set of stairs. Up one level and into a passage that took you to another passage...aw crap, lost already. Its been 11 years since I had to find that room. Just don't remember. Oh well. Think you will get my point.

Not saying don't do it. Not saying I can't wait for them to sink that thing. Just got back from the Speigel Grove and only saw the back half of it in 2 dives. I can't WAIT to do that one. Just approach it with EXTREME caution. If you haven't ever been on an aircraft carrier, you just can't imagine how confusing it is on the inside.

Hope this post has been amusing as well has helpful.

 

[Seabear70]

Well ,the Idea is that on the first full penetration to stick with the central corridor. That may not be possible depending on the condition of the carrier. And that's why I'm planning on taking 9months to a year to prep for this dive. I'm going to study whatever pics come back from it, and try to get he plans to allow me to figure out the best method. Initally, I do not plan on doing a lot of exploring... Mainly just a pass through. On dives after that I may try to go to some more interesting places in the hull, but the Idea is to do this safely.

In addition, I'm planning on following all normal penetration safty methods running a reel, etc... worse case senerio with the reel, I have to haul it in to find out where I've been.

Currently I am posting on this Idea to get some help hammering out the details, so please continue to shoot holes in anything that seems to be a problem.

And, yes, I have been on a carrier, big mothers aren't they? That's part of what makes this so interesting.

 

[Seabear70]

Ok, I'd originally planned on doing a little bit on the mindset and dedication for this dive, but let's do a little bit of homework before we get into that.

http://www.vnh.org/DivingManual/DiveManRev4ChangeA.pdf

Above is a link to the Navy Dive Manual. On page 9-60 you'll find the charts for the depth range we're most likely looking at. Currently I am probably planning for a deeper depth than will actually be required, but that can be adjusted as new information becomes available.

Now, if we assume that the depest the divers would have to go is 200' and they spend 60 mins there, then we have a decompression obligation of just over 200 minutes. Now, it has been a while since I had to work this out for scuba, but I believe that gives us an in water time of just under four and a half hours. That's a lot of air to carry, but that can be worked out. I am not certain of my rate of consumption at 200', but before I attempt this dive I will know.

Now, figure that it might take what, 5 mins to decend to the entrance point. That leaves 55 mins of bottom time. It will likely take in the neighboorhood of a half hour to penetrate through the ship, this leaves 25 mins of left over time for photos, emergencies, etc.

So far this dive looks doable, but it obviously will take considerably more planning. The actual planning will have to wait till more information is available.

 

[pt40fathoms]

Please don't take this the wrong way, I mean you no insult. But from the nature of your post and the way in which you have worded them. I am forced to conclude that your diving knowledge may not be as complete as it should be in order to conduct a dive such as the one you are describing. Merely looking at the technical aspects of the dive, few people would be able to do a 1 hour dive to 210 feet on open circuit scuba. Your optimal bottom gas would still require you to be in deco for over 3 1/2 hours, assuming you could carry the required stage bottles and use optimal mix on both descent and ascent. And the amount of bottom gas used, without any reserve, accounting for a .6cu/min consumption rate would be over 400 cubic feet! That’s without ANY reserve factored in. With that in mind, I hope you can see where the impression that you need some experience and time to learn comes from.

It sounds like the wreck will be a great dive. But don't rush in, gain some experience and bottom time in progressively more demanding dives. The wreck isn't going anywhere anytime soon after they sink it.

 

[Knavey]

It sounds as if you are approaching it with the right mind set. Keep in mind that I am neither a tech or wreck diver so all of the stuff that goes into those dive plans is something I have never ever had experience with. The one thing that I have had though, is 4 years of wandering the halls of one of those things. In those 4 years, I probably never saw 1/2 of the spaces on it.

Just a couple of thoughts that occur to me...

If its upright (which remains to be seen ie. SG down in the Keys hehehe), why not start with the superstructure. Gives you the "shallower" dives to familiarize yourself with the Navy "style" of building stuff. Its possible to get lost in the tower, just not probable. That place has a lot of rooms, but its not very wide.

After that possibly tackle the hanger bay area. Lots of rooms off of that. We had jet repair shops aft, and a bunch of stuff forward of the bays. Bet there would be about 15-20 rooms immeadiately off the bay without even going any farther.

The area between the flight deck and the overhead of the hanger bay was mainly offices and berthing. Officer country was up there also. One of the main passages fwd-aft was on the level just under the flight deck. Take you a year to dive all of those areas.

The other main fwd-aft passages were on the deck just under the hanger bay. That was the deck that had the mess decks, medical, more offices, and ladders and stairwells on it that accessed all the lower decks. Entrances to the engine rooms were off of that deck also.

And then of course the engine rooms. Bet you could spend many dives just wandering around in them also. Wonder how much is going to be accessible, or if they are going to seal off sections of the ship?

I must say I envy you a bit. I do look forward to a trip report when you finally make those dives.

 

[Seabear70]

It sounds like the wreck will be a great dive. But don't rush in, gain some experience and bottom time in progressively more demanding dives. The wreck isn't going anywhere anytime soon after they sink it.

I'm not going to rush into anything... There is a reason I am going to take a year to plan this dive. I want to come back alive.

I am also not going to assume anything, for example, the .6 cubic foot per minute that you referenced. I will be checking that out in similar depths when I can verify the depths involved, f I go with the assumption that will only use a certain amount of air then factor in a reserve, I may be n for a big supprise. It is possible that to acomplish what I want, I may not have to go to 200 ft. An aircraft carrier as was pointed out is a big vessel. At this point, I plan on doing a lot of running, a lot of research, and a lot of diving over the next year to plan this dive.

Please folks, I understand that I would be a lot more comfortable doing something like this with surface supply and a support crew, but I'm not going to be jumpng off of a boat tomarrow with a MAG light and a snorkel to try this. I am planning this thing as methodically as I can, and training for it the same way.

 

[Seabear70]

Ok, for the best dive possible I'd like to take a couple of years to familliarize myself with the wreck. That's not practical. I am guessing that if I assemble a team of say 4 divers for the penetration, and maybe 4 more for support, that I'll have something like 3-4 days to do the job.

Because of that, my target is the central passageway. Unfortunately, it's probably the most boring area of the ship, but that's the way it goes.

Now, I am assuming that the ship will either be upright or on it's side, either works for my plan. If on the other hand it winds up upside down, the dive is pretty much off except to see the sights. I can just imagine that thing proped up on the super structure, you couldn't pay me enough to go under it.

In future dives I would like to see more of the ship. It's a facinating piece of American history, but right now, I've got my sights set on a specific target, the central passageway.