What is involved in diving deeper?

[Sweet Tooth]

I am interested in doing some deeper dives and am beginning the process of finding out exactly what is involved.
I've been diving since 2000 off the FL Panhandle, but my deepest dive has been ~120fsw. I mostly dive Nitrox and have a Suunto Mosquito computer, Al 80s and a 9 cu ft pony bottle. There are some wrecks I'd like to dive from 150' all the way down to 300' and have my own boat, a Tiara 3600.
What am I looking at as far as education/certification and equipment such as larger tanks or a better computer?
I'd also like to know how the dives are actually handled with respect to anchoring vs marker buoy, how to handle the boat if you're drifting during deco etc. I'll probably want to start the actual deeper diving next spring, but want to start the education and evaluation process now.
Thanks in advance.

[Teh Wicked]

Say good bye to those Aluminum 80 tanks, I wouldnt dive those in deep water if you paid me. Some guys use them for different reasons while deep diving but hardly ever do you see people using them as a back gas.

You need to find a technical instructor in your area and speak with them. It would be a huge benefit to find one that in into spearfishing as well. This way he can instruct youa little more about what your getting into. Also be prepared to start digging into your wallet, I just done a entry level helium course so i can dive to 150' and the class alone was $350 and I still need to do checkout dives.

[jadairiii]

I am interested in doing some deeper dives and am beginning the process of finding out exactly what is involved.
I've been diving since 2000 off the FL Panhandle, but my deepest dive has been ~120fsw. I mostly dive Nitrox and have a Suunto Mosquito computer, Al 80s and a 9 cu ft pony bottle. There are some wrecks I'd like to dive from 150' all the way down to 300' and have my own boat, a Tiara 3600.
What am I looking at as far as education/certification and equipment such as larger tanks or a better computer?
I'd also like to know how the dives are actually handled with respect to anchoring vs marker buoy, how to handle the boat if you're drifting during deco etc. I'll probably want to start the actual deeper diving next spring, but want to start the education and evaluation process now.
Thanks in advance.

http://www.thedecostop.com/

http://www.thetechdiver.com/

It's a start.

[Sweet Tooth]

Thanks for the replies. I want to be clear up front that I'm not looking to substitute a couple of posts on the web for qualified instruction, just trying to get an idea of what the cost/benefits would be and if this is something I really want to pursue.
Would a single 120 and a larger pony be suitable tank wise? At what depth should I really start to consider doubles?
How are dives at these depths done, i.e do you typically anchor the boat or dive down the line of a marker buoy? I can see advantages and disadvantages to each method. FWIW we prefer to "bounce dive" our current depths so the boat is free to pick up a diver anywhere. Obviously I'm gonna need a buddy or two to do this with and want to make sure they'll be good with going the extra mile as well.

Thanks again

[jadairiii]

Thanks for the replies. I want to be clear up front that I'm not looking to substitute a couple of posts on the web for qualified instruction, just trying to get an idea of what the cost/benefits would be and if this is something I really want to pursue.
Would a single 120 and a larger pony be suitable tank wise? At what depth should I really start to consider doubles?
How are dives at these depths done, i.e do you typically anchor the boat or dive down the line of a marker buoy? I can see advantages and disadvantages to each method. FWIW we prefer to "bounce dive" our current depths so the boat is free to pick up a diver anywhere. Obviously I'm gonna need a buddy or two to do this with and want to make sure they'll be good with going the extra mile as well.

Thanks again

There is no simple answer, when diving deeper and accumulating a decompression requirement, you enter an "overhead" environment, meaning that you can not safely ascend directly to the surface. The gear you take is dependant on the "mission" of the dive and whether you choose to dive with a buddy or solo. How you conduct that “mission” is also dependant on many factors, there is no “right” answer. Although this and the other diving web sites are replete with how “not to do it”. When you ask questions like yours you will get answers from divers that routinely dive below 200 on air with a single 80 to divers that will not venture to those depths without doubles with trimix and 2 deco gases.

So before you run out and buy new gear contact a few tech instructors and speak with them, find one that you are comfortable with and seems to be well respected throughout the technical diving community (that is the key point).

On the other hand if you just want to learn via the "school of hard knocks", expect to buy lots of gear that a few years from now you will realize is useless. Most new tech divers feel the need to clip to themselves just about everything they can find to buy at the LDS assuming that with a good credit card you can then violate the laws of physics. You just may end up killing yourself. Good luck

John

[Sweet Tooth]

I was hoping for something along the lines of:
Up to depth X you can use air or Nitrox (% dependent on MOD of course)
From X to Y you can use air but plan on deco stops
Beyond Z you should really look at trimix

It sounds though, like with so many things; It's just not that simple. With degrees in mechanical and bioengineering I fully respect the ability of the laws of physics to bitch slap one back into reality and I have no desire to spend a semester of the hard knocks school at that kind of depth.
It sounds like my next step is to find a good instructor. Does anyone have any recommendations (or possibly more importantly anti recommendations) for an instructor in the FL Panhandle?

Thanks again for the advice, particularly pointing out that this is an "overhead" environment; good way for me to think about it I believe.

[FredT]

Actually it IS that simple.
OTOH diving nitrox or air with planned deco isn't necessarily that simple if you extend your bottom times to need more than one (memorized) stop and keep your Oxtox limits well under control.

Diving Trimix or other custom breathe gas is as simple as breating in and out, and in depths over about 150 the wisest choice if you have a bottom and a square well planned profile. Hunting kind of screws that well planned profile thing, so find a good instructor who will teach you what you need to know to stay alive, not just what the agency is preaching that week.

One I've talked to on thedecostop.com in your area is runawaylobster. PM her there for more info but she seems more than competent and may do private lessons..

Edit.
Sorry, my bad. She's actually out of Miami, on the other side of cave country.
http://runawaylobster.com/

[black1]

call this man, one of the best out there as far as expirience and knowledge of diving deeper and a great guy.


Pompano Beach, Florida Tech Instructor Jim Mims is the President and Chief Technical Instructor at Ocean Diving Inc. He is an accomplished boat captain and also serves on the Board of Advisors for IANTD. Captain Jim has been teaching diving since 1977 and founded Ocean Diving Inc. in 1979. Ocean Diving Inc. offers IANTD and DAN Instructor Certification courses as well as IANTD Recreational, Technical and Rebreather Diver Certification courses. Contact Jim Mims at his phone number 954-849-DEEP or his e-mail DiveTek@OceanDiving.com

[ObieWan2bWet]

I was hoping for something along the lines of:
Up to depth X you can use air or Nitrox (% dependent on MOD of course)
From X to Y you can use air but plan on deco stops
Beyond Z you should really look at trimix...



When you can answer those questions instead of asking them you shall be ready to walk the rice paper grasshopper.

Proper training and experience. No other way.

[Sweet Tooth]

That's why I'm asking the questions, so eventually I'll be able to answer them.

Any thoughts on Jeff Loflin as an instructor for what I'm wanting to do?

Thanks

[Pierce07]

I strongly wouldn't recommend shooting fish on Trimix. While diving trimix your ascent rates change, deco obligations increase, and you need to carry much more equipment. Also with trimix you don't run off what your computer says you have to plan the dive then execute your plan. If you over stay 2 or 3 minutes on the bottom it completely changes your Deco times.

I've taken 25% to 150-160 plenty of times and I know personally that's where I start to feel a little narced.

Diving in doubles is enough of a task by itself. I personally wouldn't recommend doubles and spearfishing.

[jadairiii]

.... deco obligations increase,

Incorrect

...and you need to carry much more equipment. .

Incorrect

.. If you over stay 2 or 3 minutes on the bottom it completely changes your Deco times. .


Incorrect


....Jeff Loflin....

I would suggest going over on The Deco Stop to ask about tech instructors. You will get a lot more feedback.

John

[FredT]

The primary thrust of modern tech diving is to go down and look &/or take pictures, not go down and do things. There are several issues with CO2 buildup that make working very hard very deep for an extended time period problematic. Not impossible with proper planning, but problematic without it.

I agree that The Deco Stop is a good source, but whoever you talk to make sure the instructor understands exactly why you want to learn about the tools before you start training with them. The current crop of tech instructors is heavily biased towards cave and wreck penetration diving, not spearfishing.

[Pierce07]

Incorrect

Incorrect

Incorrect

I would suggest going over on The Deco Stop to ask about tech instructors. You will get a lot more feedback.

John

Well you should really look into your deco planner then. A diver to 215 feet with a run time of 20 minutes with a 18% 02 mix runs 70 minutes. If you over stay 3 minutes of bottom time you are looking at a 83 minute dive both with a 70% mix for deco. I don't know many people that blow off 10 minutes of deco.

20 Min Dive:

215- 20
First stop- 110 for 1 Min
100- 1 min
90- 1 min
80- 1 min
70-3 min
60- 3 min
50- 6 min
40- 4 min (switch to 70%)
30- 4 min
20- 9min
10- 14min

215-23 minutes
100- 1
90-2
80- 2
70- 3
60- 5
50- 6
40- 4 (switch to 70%)
30- 7
20- 10
10- 16

If you are going to be diving deep then you will most likely have to carry a stage bottle which is more gear. Unless you're going to hang it which is taught in no tech class. Also if you are going to dive trimix correctly you will either have to buy 2 computers or run tables and have 2 bottoms times. Not including the doubles or H-valve.

Yes going to Deco Stop will provide you with help. I'm also a member over there. www.tdisdi.com offers a instructor search for people in your area.

And to take the class I don't know of any instructor the will do your advanced Nitrox/ Deco Procedures w/o doubles, lift bag, deco bottle, two bottoms timers, back up lights.

[jadairiii]

Well you should really look into your deco planner then. A diver to 215 feet with a run time of 20 minutes with a 18% 02 mix runs 70 minutes. If you over stay 3 minutes of bottom time you are looking at a 83 minute dive both with a 70% mix for deco. I don't know many people that blow off 10 minutes of deco..

Whether you’re using Decom, DecoPlanner, V-Planner or Naui’s RGBM/GAP (or any other, I have most of them, they are fun to play with), all of the deco programs are entirely or partially based on Bühlmann. I can (and have) run Decom tables that look identical to DecoPlanner, RGBM or V-Planner.

And here is the problem with them all; they penalize you on shallow stops for using Helium because Bühlmann tables were designed for air. They hang you shallow to make up for any issues deep.

Point of all this, Tables are nice to look at but they only do an average job at modeling decompression schedules. They should be used as guides not gospel.

There are instructors out there that understand this, find them. As FredT stated make sure the instructor knows what you want to use this knowledge for, but ultimately, regardless of how you dive, the physics does not change.

John

[dagodiver]

I strongly wouldn't recommend shooting fish on Trimix. While diving trimix your ascent rates change, deco obligations increase, and you need to carry much more equipment. Also with trimix you don't run off what your computer says you have to plan the dive then execute your plan. If you over stay 2 or 3 minutes on the bottom it completely changes your Deco times.

I've taken 25% to 150-160 plenty of times and I know personally that's where I start to feel a little narced.

Diving in doubles is enough of a task by itself. I personally wouldn't recommend doubles and spearfishing.


All of that is bogus information.
I strongly would recommend doing it no other way in water deeper than 150 ish...
Then how about an RB and sidemount 40's...works for me. I would post the pic's but hate arguing with people. Well actually it is kind of fun.
Doubles actually trim out better than singles. A set of 80's wet with a single deco gas can get some serious work or fish killing done when used properly.
Like John stated physics are just that.
Get some training and have fun.!

Dago.

[GUNRUNNER]

Spearing on doubles? thats just crazy talk.

[dagodiver]

Spearing on doubles? thats just crazy talk.

Love the avitar.! Doubles deco gas backplate wing and long blades, now that will get some shit done.!

Dago.

[Mobile Diver]

I have to say, you better listen to Dago. He has logged a LOT of time with doubles & trimix.

I don't tech dive, but I have learned a lot from observing the way tech divers do things. You are obviously educated, so do some research & you can find real answers. Just understand that some divers can do things safely others cannot. Find your limits & don't exceed them.

[seadogger]

why would you want to go thru all that sh..t to kill fish that you can kill at 90-110 ft ? Divers that get stupid because they want to go "deeper" and be the macho hunter are the ones you read about in the obituaries !! Stay safe, use one good computer, buy you a couple of single steel 120's, put your catch on a lift bag, don't anchor...jug your spot and dive the jug and.........keep a 6 ft safety sausage and whistle on you at all times and one more item...get a 18cft pony bottle for your emergency air. I dive up to 120 fsw a lot. I will kill anything you can at 160-200 ft. Just remember, be safe, plan your dive and........dive your plan. Good luck

[waterpirate]

You have some really good questions that need to be answered either by you, your mentor, your instructor, or my favorite all of the above. If you are going to do anything beyond 100fsw you need intro to deco and advanced nitrox as a minimum to be safe. Shooting fish at that depth and thinking you can allways maintain a ndl time is crazy. As allways the responses in this thread are really good, and just plain crap. A instructor or mentor will help you see the differance.
In my opinion deep diving should allways be a mental exercise in mitigating risk. To achieve this goal I allways dive manifolded doubles, put helium in my mix below 130, carry deco gas, and plan for the worst.
My lightbulb moment that got me to stop diving single 120's was when I had a good understanding of the deco models and the % that went into creating them. When I understood that, I knew that I did not want to make a direct ascent to the surface for any reason from any depth ever.
Good luck on your journey, and if you are successfull your wallet will truly be alot lighter when you get to where you are going.
Eric

[dagodiver]

why would you want to go thru all that sh..t to kill fish that you can kill at 90-110 ft ? Divers that get stupid because they want to go "deeper" and be the macho hunter are the ones you read about in the obituaries !! Stay safe, use one good computer, buy you a couple of single steel 120's, put your catch on a lift bag, don't anchor...jug your spot and dive the jug and.........keep a 6 ft safety sausage and whistle on you at all times and one more item...get a 18cft pony bottle for your emergency air. I dive up to 120 fsw a lot. I will kill anything you can at 160-200 ft. Just remember, be safe, plan your dive and........dive your plan. Good luck



Horse shit.! Really....how about all the bug hunters in less that 30 feet of water and all the tragic stuff happening with free diving latley.....you talk with no reality. 1 foot or 300 foot i cant breath under either one. Be safe.

Dago.

[captron]

I dive deep & Spear fish, I use a computer With 4 dive tables allso, anything that can go wrong will think redundancy & extra air. If you shout the fish the dive is over. Only at the begining of the dive. At the end it's to late. my next 2 dives is at 175ft sw And 270ft. sw. for 28 min. At that depth it is totaly different.