View Full Version : Andrea Doria Trip Report
theskull
July 18th, 2006, 11:19 PM
Joel Silverstein’s 50 Anniversary Expedition aboard the John Jack out of Montauk, NY.
After months of preparations I loaded up a rental SUV with my gear and 3 complete sets of tanks—steel doubles containing TMX 17/50, steel LP 72s containing EAN 50, steel LP 45s containing Oxygen, and Al 14s containing Argon for drysuit inflation. Required gear also included 2 reels, 2 liftbags, 2 jon lines, primary light & 2 backups, 3 cutting tools, surface signal devices, mixed gas dive computers and/or deco tables. Most optimistic projection for 3 days on the wreck was 5 dives, and least optimistic was a complete cancellation, all depending on weather and sea conditions.
The weather and surface conditions turned out beautiful for us, but the currents not quite as favorable. I completed 2 dives on the Doria, which was 1 more than I required for a successful trip personally. My first dive, on the afternoon of the first day, was glorious—my buddy (also a cave diver making his first Doria dive) and I made a smooth descent past thousands of jellyfish! through a mild current to the tie-in at 190 ft. From there we dropped to the next level of the wreck at 210 ft. and explored back and forth, poking our heads in through openings and watching for artifacts while admiring the massiveness of the wreck and the beauty of the reef which has formed on it as well as the variety of fish inhabitants. We discovered a loose porthole, but left it behind rather than complicate our first dive with a lift bag retrieval. After a 15 minute bottom time we headed up to begin our 45 minutes of deco stops.
Day 2 I sat out. The current screamed all day long, with a short break in the late afternoon. Many jumped in to make a dive during this short interval, but I chose to be more cautious in case the current picked up again during the dive. (One of my buddies remarked that it was better to be on the boat wishing you were in the water than in the water wishing you had not left the boat.) There was also a heavy fog, so a drifting diver could have been difficult to locate. One of our teams did get too far down-current of our ascent line to make it back and had the good fortune to come upon the ascent line of the other charter boat that was on the wreck that day—their zodiac boat towed our divers back to us.
The third day our plan was to begin diving at 6 am to hopefully beat the morning current. I splashed in at 7 am with 2 buddies to a moderate shallow current that got stronger the deeper we went. Even with the weight of all those full tanks and my ankle weights, BC empty, I had to pull and kick to get down the descent line against the increasing current. The anchor line was vibrating and singing in the current like a piano string. We reached the tie-in at 190 ft., looked around a little, pulled along the top of the wreck while keeping a good grip, and returned to the ascent line just a handful of minutes later—not wanting to create a big deco obligation during which we knew we would be flying from the anchor line like flags in the breeze. After a descent and bottom time of 11 minutes we had 28 minutes in deco stops on the way back to the surface.
Water conditions were 20-40 ft. visiblity, 52 F water temp at the surface and down to 20 ft. deep, and 46 F the rest of the way down. The Doria is enormous and incredible!!
Highlights—beyond the obvious one of being one of only several hundred divers to dive this very famous wreck included:
Diving with Joel Silverstein, a tech diving authority and expedition leader who has made over 50 dives on the Doria.
Diving with Gary Gilligan, one of the pioneers of tech diving on the Doria, and frequent crew member on Doria expeditions.
Diving with Kevin McMurray, author of Deep Descent (Andrea Doria) and Dark Descent (Empress of Ireland), who was authoring a short news piece for CBS during our trip to augment a 50th anniversary news piece planned for later this month.
With 10 paying participants and 5 diving crew members, observing and discussing 15 different gear configurations including everything except the strict DIR setup; we had everything from a rebreather diver using yellow split fins to a couple divers with the classic NE wreck diver setup of a 40 cu ft pony bottle mounted between the double tanks with its own reg around the neck as a bail-out breathing supply. Everyone had a setup that worked for them for the diving they were doing!
Ongoing deterioration of the wreck is making new areas accessible and releasing many artifacts into easy reach. Many of us still came away empty-handed, mostly due to the limited number of dives, difficulty of dealing with the currents, and added agenda of getting some UW photos and video for the CBS news piece. But some of our members came away with a little bit of china, a couple window frames, a porthole, and even a bathroom sink.
Best of all, we all returned alive and unhurt! It was indeed an experience I’ll cherish.
theskull
juls64
July 18th, 2006, 11:50 PM
Wow! Thanks for the report.
It sounds like a really remarkable trip. Thanks for sharing with us.
Julie
nauifins73
July 19th, 2006, 12:37 AM
Great report - so glad it was a successful trip!!
MgicTwnger
July 19th, 2006, 06:49 AM
Man, you have climbed Everest!
steve2281
July 19th, 2006, 07:09 AM
Interesting report. Thanks.
do it easy
July 19th, 2006, 07:43 AM
Wow, first the Abe Davis award, and now the Doria. I'm not worthy to O2 clean your tanks (you wouldn't want me to do it anyway). :D The trip report is great, I always wondered what kinds of divers dove the Doria.
DeepDiverBob
July 19th, 2006, 07:46 AM
excellent report. I am most excioted about that last part, where everbody made it back safe. I'm looking forward to seeing that news report. I'll have the Tivo ready for sure.
theskull
July 19th, 2006, 10:01 AM
Wow, first the Abe Davis award, and now the Doria. I'm not worthy to O2 clean your tanks (you wouldn't want me to do it anyway). :D The trip report is great, I always wondered what kinds of divers dove the Doria.
And for my next trick . . . It's time to do some easier stuff and check out some places like Cozumel. Not going to keep pushing the envelope.
What kind of divers do the Doria? They were all just a bunch of guys who are very practiced and comfortable with their habits and procedures--and who respond to problems with the same casual practiced responses to solve whatever problems arise. And there were definitely some problems encountered. They were mostly first-timers like me (also my last time--again, don't need to keep pushing the envelope) but our leader and most of the crew had been on the dive many times. But also like me, the other first-timers had already made many many dives of similar or greater complexity and to similar or greater depths so that this dive was not a stretch in spite of having the aura of "Mt. Everest".
theskull
And I HATE to O2 clean tanks, so you may do it for me any time.
scububa
July 19th, 2006, 10:44 AM
Bill,
Great report. I was waiting for this one. Glad you had a nice trip and didn't get blown out or have everything over-shadowed by rough sea-sick conditions.
When you consider the equipment, logistics, weather, mix of people, and the diving extremes, there is such a tremendous potential of risks that it is easy to understand why you are one of the few and the proud.
Having recently gotten to the Keys and been excited to dive on the Spiegel Grove, Duane and Eagle, I can't imagine how incredible it would be to dive the Andrea Doria.
Congradulations!
Jim
Laser
July 19th, 2006, 07:57 PM
Sounds like an awesome experience.
Just a question......why steel deco cylinders?
Thanks
Tim
texdiveguy
July 19th, 2006, 08:01 PM
Great report,,,,and Bill thanks again for the PM. Alan
theskull
July 20th, 2006, 07:53 AM
Sounds like an awesome experience.
Just a question......why steel deco cylinders?
Thanks
Tim
I always go with steel for my O2 for the obvious reasons.
For the EAN 50 I took steel for this trip just for the extra weight so I wouldn't have to wear any lead to offset the added buoyancy of the salt water. We were only using the 2 stages so balance wasn't an issue at all--I should also add that I wear my stages on both sides.
theskull
do it easy
July 20th, 2006, 08:08 PM
I'm not exactly a rocket scientist, so,
1) What are the obvious reasons for the steel O2 bottle? No need to boost or greater volume when boosted, something I missed?
2) Do you drop your deco bottles when you get to the wreck or do you keep them with you? Also, do you have a shell or neoprene DS?
Originally, I thought the steel tanks were just leftovers from cave diving, so now I'm curious...
theskull
July 20th, 2006, 10:44 PM
I'm not exactly a rocket scientist, so,
1) What are the obvious reasons for the steel O2 bottle? No need to boost or greater volume when boosted, something I missed?
2) Do you drop your deco bottles when you get to the wreck or do you keep them with you? Also, do you have a shell or neoprene DS?
Originally, I thought the steel tanks were just leftovers from cave diving, so now I'm curious...
1. Reasons for steel O2 bottle include:
*Except in N Florida, it is typical to only have access to O2 fills of app. 2000 psi.--with a steel LP 45 this still gives you app. 34 cu. ft. of gas, as opposed to 2000 psi in an Al 40 which only gives you app. 27 cu. ft. of gas.
*Even if you can get high pressure O2 fills, O2 is considered much more hazardous to handle at high pressures.
*As a cave diver, I most often am dropping off my O2 bottle at the beginning of the dive and picking it up at the end; when ending the dive with doubles less than half-full and an aluminum stage or two that are near-empty and buoyant, it is very nice to pick up that heavy O2 bottle when I am at my lightest, my shallowest, and wanting to put a little more gas in my drysuit! Actually, this reasoning holds true even on open water dives with multiple stages; good to have some ballast to offset the buoyant aluminum tanks you are still wearing at the end of the dive.
*A steel 45 is small enough that it is not that heavy and is easy to handle; on the occasions when I have stacked my stages all on the left (the others being Al 80s) there still is not a balance issue. I have made a number of dives with all stages on the left side to see what the big deal is, and I just don't like it as much.
2. I don't drop my stages when diving open water, which includes wrecks. If they contain gas I expect to "need" on the dive, they are staying with me. Unlike cave diving, in open water you cannot guarantee that you will be coming back the same way to find your bottles waiting for you; some serious accidents and deaths have resulted from divers making this mistake. Exceptions might come along, such as a wreck small enough that I know I'll be exiting the same way I entered or possibly a need to get in to a small entrance to aid another diver who is having issues.
2. a. I have a shell dry suit, but don't see how this affects any of the above reasons. Buoyancy is buoyancy, and insulation is insulation. You're either getting your buoyancy and insulation from neoprene AND undergarments or from thicker undergarments.
My reasons are not universally accepted or followed (none are!), but they are quite common among the majority of my dive buddies. Perhaps relevant is that the majority of my dive buddies are cave divers who dive deep, cold water caves.
theskull
do it easy
July 21st, 2006, 07:36 AM
Thanks for the insight. There is a lot of talk on the net about why aluminum tanks are the greatest thing since sliced bread; I wanted to hear another side of the story.
Regarding the shell vs neoprene question, I think they are equivalent, as long as you don't have to add a lot of weight to remain neutral. I have a DC compressed neoprene suit with steel tanks in fresh water, so I don't wear a weight belt, although I do have a steel plate. I've been thinking ahead to my next drysuit and I think it might be a shell suit, simply so that I can fluff it up a bit more and trade neoprene for insulation. It's friggin cold out there. :D
ppo2_diver
July 21st, 2006, 09:05 AM
I switched from a DC neo suit to a shell suit. Much better in a shell. Even with a single steel tank, I don't need any weight. Plus my shell suit is "roomier" than my neo suit. So if anyone wants to buy a DC dry suit, I've got one that I can part with.
As for steel stages, you solve one problem (more O2) but create another (over weighted). My thinking is that I would rather do longer deco with 50% or shorten my BT to accomodate 2000 psi in an AL40 than to risk being overweighted and not able to make it back. In wreck diving, there is a greater chance of a catastrophic wing failure (i.e. puncture) than in just open water diving. If I'm so overweighted that I can't swim back to the anchor line, I'm fk'ed. I'd have to ditch the steel O2 bottle. Now I have to go to contingency tables cause I won't have my O2 to deco with. Just my thoughts.
do it easy
July 21st, 2006, 07:21 PM
I simulated a wing failure one day. I can't remember if I was wearing 1 or 2 AL80s with my LP95s, but I swam up from 20' fresh. It was a bear, but I did it- the ascent was real slow! A little later on, I did the same thing, but I inflated my drysuit and was just fine. My neckseal was on the verge of burping, but it didn't. Under real Super High Intensity Training conditions, I wouldn't feel comfortable trusting my neck seal not to burp and send me on a quick ride. I would prefer dropping weight or hanging on a bag rather than swimming it up and trying to hold stops. Of course if I holed my wing, drysuit and my liftbag...
theskull
July 22nd, 2006, 10:12 AM
I switched from a DC neo suit to a shell suit. Much better in a shell. Even with a single steel tank, I don't need any weight. Plus my shell suit is "roomier" than my neo suit. So if anyone wants to buy a DC dry suit, I've got one that I can part with.
As for steel stages, you solve one problem (more O2) but create another (over weighted). My thinking is that I would rather do longer deco with 50% or shorten my BT to accomodate 2000 psi in an AL40 than to risk being overweighted and not able to make it back. In wreck diving, there is a greater chance of a catastrophic wing failure (i.e. puncture) than in just open water diving. If I'm so overweighted that I can't swim back to the anchor line, I'm fk'ed. I'd have to ditch the steel O2 bottle. Now I have to go to contingency tables cause I won't have my O2 to deco with. Just my thoughts.
Sounds more like an over-thinking problem than an overweighted problem.
First, weight depends on the diver--I don't dive overweighted, I just trade steel tank for needing to wear lead. And with just the O2 in steel, it is more like the drop-weights the cave divers used to use to help make their initial descent and then left behind during the dive to be retrieved at the end of the dive to help with a slow ascent.
Doing deco on just 50% is not the wisest thing when doing bottom time on a high helium mix. It is an acceptable contingency but a foolish plan.
In the extremely unlikely event of a catastrophic wing failure, my suit has enough buoyancy--I have practiced it. And even if I did have difficulty, I could ditch my 50% bottle to lighten my load--yes, if I had to pick a deco gas to give up on a Trimix dive it would definitely be the 50%.
Have you had any actual Trimix training, or just read about it on scubaboard?
theskull
ppo2_diver
July 22nd, 2006, 12:18 PM
I have had trimix training.
theskull
July 22nd, 2006, 01:40 PM
I have had trimix training.
So your opinions are at least informed if perhaps a bit polarized. Might have presented them as valid options and opinions rather than assuming that a single small steel tank would be dangerous overweighting for ME while diving MY rig.
I would expect to be attacked and second-guessed on scubaboard, and would not bother to post a dive report there.
Here we tend to be a bit friendlier. I expect questions. I answer them not as a be-all end-all authority but as someone who has some valid experience and has made choices for reasons which I am happy to share. My choices may not be yours, and they may not even still be mine a year from now--but they are working for me now, they have been well thought out, and have been time tested on a good number of dives.
theskull
ppo2_diver
July 22nd, 2006, 01:54 PM
I didn't attack anybody. I just said that I prefer not to dive steel stages for the reasons I mentioned. People can dive how ever they want. I never tell people to dive my way.
theskull
July 22nd, 2006, 02:17 PM
I didn't attack anybody. I just said that I prefer not to dive steel stages for the reasons I mentioned. People can dive how ever they want. I never tell people to dive my way.
Sounded preachy to me. Perhaps I read more into it than what was intended. The whole "communiction thing" can be tricky. :)
Happy diving to ya,
theskull
steve2281
July 22nd, 2006, 04:35 PM
Have you had any actual Trimix training, or just read about it on scubaboard?
theskull
No tri-mix training here, but I did stay at a Holiday Inn Express last night.
Thought I would lighten the mood a bit. Part of my extraordinary since of humor.
ABSOUUTELY, no offense intended.
Rodney King once said, "___". Well, I forgot what he said, but I know it was good.
steve
theskull
July 22nd, 2006, 09:25 PM
No tri-mix training here, but I did stay at a Holiday Inn Express last night.
Thought I would lighten the mood a bit. Part of my extraordinary since of humor.
ABSOUUTELY, no offense intended.
Rodney King once said, "___". Well, I forgot what he said, but I know it was good.
steve
Hi Steve,
I'll be staying at a Holiday Inn Express this week. I forget what Rodney King said, too, but I do remember he got arrested again pretty quickly for breaking more laws.
See ya around,
theskull
steve2281
July 22nd, 2006, 10:27 PM
"Why can't we all just, get along" Rodney King
MgicTwnger
July 23rd, 2006, 06:03 AM
I'll be staying at a Holiday Inn Express this week.
Seriously? Are you talking about Waukegan?
theskull
July 23rd, 2006, 11:06 AM
Seriously? Are you talking about Waukegan?
Sort of. I'll be staying at the HIE this week while working in Rockford, IL.
Will be rooming with youse guys in Waukegan. I thought Bob told me it was going to be a Days Inn, though.
It's seriously about time I dived some Great Lakes wrecks. I've had 3 previous trips booked that all got cancelled for various unavoidable reasons. Can't wait!
theskull
MgicTwnger
July 23rd, 2006, 12:48 PM
I can't believe that you've dived the Doria and not lake Michigan! Nothing like starting at the top.
theskull
July 23rd, 2006, 07:49 PM
I can't believe that you've dived the Doria and not lake Michigan! Nothing like starting at the top.
Started at the bottom, actually. It was my extensive cave diving that qualified me for the Doria trip, the same for the dive buddy with whom I dived on the trip--and Joel gave us trouble about it the whole time ;)
Lots of stuff I have yet to do, though. All the Great Lakes, Cozumel, Montserrat, Caymans. I'm just getting started.
theskull
divbum
July 25th, 2006, 10:21 AM
Doing deco on just 50% is not the wisest thing when doing bottom time on a high helium mix. It is an acceptable contingency but a foolish plan.
In the extremely unlikely event of a catastrophic wing failure, my suit has enough buoyancy--I have practiced it. And even if I did have difficulty, I could ditch my 50% bottle to lighten my load--yes, if I had to pick a deco gas to give up on a Trimix dive it would definitely be the 50%.
theskull[/quote]
I am very interested in hearing your reasons regarding the above statements.
theskull
July 25th, 2006, 05:56 PM
Doing deco on just 50% is not the wisest thing when doing bottom time on a high helium mix. It is an acceptable contingency but a foolish plan.
In the extremely unlikely event of a catastrophic wing failure, my suit has enough buoyancy--I have practiced it. And even if I did have difficulty, I could ditch my 50% bottle to lighten my load--yes, if I had to pick a deco gas to give up on a Trimix dive it would definitely be the 50%.
theskull
I am very interested in hearing your reasons regarding the above statements.[/quote]
Information gleaned from the texts used in my Trimix courses, diving practices of the experienced Trimix divers I have dived with, and computer models. Chief reason is the value of the Oxygen window at 20 feet, which most believe to be much more valuable than the 50% window at 70 feet, especially since the shallow stops are the more critical ones.
Again, this is a specific instance. I want to have both deco gases when possible. And on shallower dives with less Helium content it wouldn't be as big a deal. But at 200+ ft. with 50% Helium I would opt for the Oxygen if I HAD to choose.
The choice I'd really like is to go back in time and not respond to the DIR-tinged comments regarding my equipment choices for this trip! ;)
theskull
divbum
July 25th, 2006, 06:31 PM
I find your reasons interesting, but I pretty much completly disagree.
I find, from practical experience of myself, and many accomplished divers I dove with the opposite to be true.
If I had to complete any planned 2- deco gas dive, the shallow gas would be the one to lose ( given proper planning) Your overall deco time is reduced by starting (or Opening the 02 window) deeper. This can be viewed in many decompression software by running a 200' dive for 20 minutes on say 18/45, then select both gases, then 50% only, and then 02 only. Respectively an RGBM model gives runtimes of 48, 52, and 67. I used an RGBM program here because they highly tout back gas to 02, but I fine three other programs I have here produce the same results (final dive time varies slightly). Next we can even compare adding 25% He to the 50% bottle to help reduce inner ear DCS vs riding all the way to 02 were the he pp is at the slightest reduction also. 58 run time vs. the 67. So either way starting decompression deeper with an increased PP02 helps move gases out better. I am open to compare any depths and times here, but just quickly looked at the above listed dive. I have always found this to be true in the past dive planning and execution.
Either way no ones plan would be foolish, just different. I am also interested in what text and articles you have read which have helped influanced your thoughts here.
Congrates on getting some good dives in. Hopefully you can make it back and get to see a little more.
DeepDiverBob
July 25th, 2006, 11:07 PM
wasnt this thread about theskulls trip to the Doria? Why are we bringing down a trip of a lifetime for most, just to argue meaningless points? AL, ST, 100%, 50%...obviosuly you have all made it back from all your dives, so you are all perfect in my eyes, now lets cut out the bickering, please.
When do you expect to get some pics from the Doria? I am curious to see what you saw.
theskull
July 25th, 2006, 11:34 PM
Hey Divbum,
I like your arguments. Very complete, practical, and factual--but I'm still going to disagree. Before I give an additional reason for choosing the Oxygen over the 50%, let me agree that above all Trimix deco is very much in the theory and practice stage still, and that we may both have very different views again a year from now as more science gets applied and more dives are made. And acknowledging this, let me also apologize for calling the 50% only plan foolish. And further, having re-read PPO2's original suggestion I think I misread his post and that he meant extending the time on the 50% so that you wouldn't need as much time on the O2 IF you had a short fill on the O2 rather than leaving the O2 off entirely to use only 50%. (I still think he was slamming me for using steel stages, though--that's OK too.)
So back to our question at hand. Total run-time of the dive and getting out of the water quicker are not my main goals, and having run many many models on this question I agree with you that the 50% gets you out faster than the O2. My main concern is getting out of the water unhurt, and every contingency plan I have seen for correcting for any deco omissions focuses on spending more time at the 20 ft stop on O2. And my additional reason for choosing O2 over 50% is that if I should experience any suspected symptoms of DCS at the end of the dive I already have O2 right there by my mouth ready to start breathing it. That is my reasoning based on what I have been taught, witnessed, and experienced so far. And while I can't argue with your reasons, I'm sticking with mine for my dives (for now).
My texts in my classes were IANTD and DSAT, but I have also read all the GUE materials. I truly am a big fan of the GUE training and DIR configuration--they have significantly influenced my diving practices and gear selections. And the tech divers with whom I have dived who were actually trained to cave dive by GUE are really quite open-minded about variations in gear choices as long as you dive with the right attitude and skills.
I did have some excellent dives, but have no plans to return for more on the Doria. My goal of diving it has been satisfied, but even more so than that I must balance the big price-tag of the dive along with the logistics of getting so many tanks with the right blends out there (or pay the exorbitant rental and helium prices on the East coast) against the very real chances that the weather and sea conditions and currents might conspire against you making any dives at the tail-end of the ordeal. I might view this very differently if I lived out there and could have a chance of crewing on the boats to get in some very affordable dives!
Have fun and dive safe,
theskull
theskull
July 25th, 2006, 11:41 PM
wasnt this thread about theskulls trip to the Doria? Why are we bringing down a trip of a lifetime for most, just to argue meaningless points? AL, ST, 100%, 50%...obviosuly you have all made it back from all your dives, so you are all perfect in my eyes, now lets cut out the bickering, please.
When do you expect to get some pics from the Doria? I am curious to see what you saw.
Hey Bob,
I welcome the discourse and I do think that gear choices and deco theory are a big part of what people are curious about regarding my trip. I sure asked alot of questions of the other divers on the trip--and I can assure you that there were many variations in gases used, gear placements, deco schedules, and computers in use; too many to get into here!
I asked about the pictures this morning, and was told that our photographer is out on some other event shooting it right now, but that the pictures should be up for us in the next few days. Will let you know when I have them. I only took a handful of top-side photos--I'll show them to you this weekend and see if you think they would be of any interest to our viewing audience. I'll definitely post some of the UW photos when I get them.
theskull
Laser
July 26th, 2006, 08:54 AM
Hey Bob,
I welcome the discourse and I do think that gear choices and deco theory are a big part of what people are curious about regarding my trip. I sure asked alot of questions of the other divers on the trip--and I can assure you that there were many variations in gases used, gear placements, deco schedules, and computers in use; too many to get into here!
I asked the original question regarding the steel stages simply because I wanted to know the thought behind it. I also find discussing the different choices of gear/gasses etc. on the bigger dives very interesting and always come away with something from the discourse. I appreciate the civil discussion of the points. Thanks.
MgicTwnger
July 26th, 2006, 08:58 AM
I asked the original question regarding the steel stages simply because I wanted to know the thought behind it. I also find discussing the different choices of gear/gasses etc. on the bigger dives very interesting and always come away with something from the discourse. I appreciate the civil discussion of the points. Thanks.
I agree. I learn a lot just listening to guys like Bill and Greg discussing this stuff. I pretty much stay away from the "other" board because of the un-civil discussions. Please note my signature.
ppo2_diver
July 26th, 2006, 08:58 AM
(I still think he was slamming me for using steel stages, though--that's OK too.)
I never slam anybody. Except Greg (aka DivBum). Just because I know I can take him. :D
divbum
July 26th, 2006, 10:40 AM
Hey Divbum,
I like your arguments. Very complete, practical, and factual--but I'm still going to disagree. Before I give an additional reason for choosing the Oxygen over the 50%, let me agree that above all Trimix deco is very much in the theory and practice stage still, and that we may both have very different views again a year from now as more science gets applied and more dives are made. And acknowledging this, let me also apologize for calling the 50% only plan foolish. And further, having re-read PPO2's original suggestion I think I misread his post and that he meant extending the time on the 50% so that you wouldn't need as much time on the O2 IF you had a short fill on the O2 rather than leaving the O2 off entirely to use only 50%. (I still think he was slamming me for using steel stages, though--that's OK too.)
So back to our question at hand. Total run-time of the dive and getting out of the water quicker are not my main goals, and having run many many models on this question I agree with you that the 50% gets you out faster than the O2. My main concern is getting out of the water unhurt, and every contingency plan I have seen for correcting for any deco omissions focuses on spending more time at the 20 ft stop on O2. And my additional reason for choosing O2 over 50% is that if I should experience any suspected symptoms of DCS at the end of the dive I already have O2 right there by my mouth ready to start breathing it. That is my reasoning based on what I have been taught, witnessed, and experienced so far. And while I can't argue with your reasons, I'm sticking with mine for my dives (for now).
My texts in my classes were IANTD and DSAT, but I have also read all the GUE materials. I truly am a big fan of the GUE training and DIR configuration--they have significantly influenced my diving practices and gear selections. And the tech divers with whom I have dived who were actually trained to cave dive by GUE are really quite open-minded about variations in gear choices as long as you dive with the right attitude and skills.
I did have some excellent dives, but have no plans to return for more on the Doria. My goal of diving it has been satisfied, but even more so than that I must balance the big price-tag of the dive along with the logistics of getting so many tanks with the right blends out there (or pay the exorbitant rental and helium prices on the East coast) against the very real chances that the weather and sea conditions and currents might conspire against you making any dives at the tail-end of the ordeal. I might view this very differently if I lived out there and could have a chance of crewing on the boats to get in some very affordable dives!
Have fun and dive safe,
theskull
Thanks for taking the time to reply. I feel it is in depth enough for the internet discussion, so I have no desire to keep toggleing back and forth. I do need to read the DSAT manual some day...
What was your overall impression of the John Jack, vessel, captian and crew, and serivces. I have a friend looking into them for next year and would like just a basic idea to forward on.
divbum
July 26th, 2006, 10:43 AM
I never slam anybody. Except Greg (aka DivBum). Just because I know I can take him. :D
August 26th and 27th... if your ready we can find out:smileychi
ppo2_diver
July 26th, 2006, 10:58 AM
August 26th and 27th... if your ready we can find out:smileychi
How about September 30? Give you some time to get into shape.
My hijack is over.
Looking forward to see Skull's pics.
theskull
July 26th, 2006, 03:15 PM
Thanks for taking the time to reply. I feel it is in depth enough for the internet discussion, so I have no desire to keep toggleing back and forth. I do need to read the DSAT manual some day...
What was your overall impression of the John Jack, vessel, captian and crew, and serivces. I have a friend looking into them for next year and would like just a basic idea to forward on.
The DSAT manual is quite good--I was really surprised by it. It is well-written and easy to follow, unlike some of the others. They did have the advantage of piggy-backing on what had already been done, and it reads more like a summary of what is currently known and thought than a technical text. It pretty much contains everything you "need" to know without overburdening you with theories and studies--I know some will consider this a fault. ;)
My impression of the John Jack is that it is very professionally run and safety oriented. Captain Zero knows his business, looks out for his customers and crew, and does what he can to please. It is definitely a dive boat rather than an excursion boat--the bunks are crowded and poorly ventiliated, the food served is very basic, and you don't want to try to take anything with you that you don't absolutely need. There are some amenities--the galley is air conditioned some of the time, there is a good quality DVD/VCR player in the galley for movie-watching, and there is an outlet at each bunk so you can recharge light batteries or other electronics. It is a larger vessel than the other charters I saw taking divers out to the Doria, so it should ride a little smoother and provide a little more safety should you have to return in high seas. If I were going to dive the Doria again, I would definitely be willing to do it on the John Jack again.
theskull
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