DCS due to reading computer wrong (I think)

[Boiler_81]

I am still interested what the OP buddy was doing and what decompression he had.

 

[MMM]

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[flots am]

You originally said your computer appeared to you to indicate a "safety stop" of 14 minutes. I am going to assume you meant it told you to do a single decompression stop of 14 minutes at normal safety stop depth. I am not familiar with that computer and its algorithm, but that would not be surprising if that were the case.

Just a "For What It's Worth": The Tec 2G will lock out and display "SOS" (or a "505 Error" as I've seen some people complain about ) if the decompression stops are ignored. I have no idea if the OP's computer did this.

flots

 

[Hintermann]

I am still interested what the OP buddy was doing and what decompression he had.

I had no specific buddy as such. We were made to dive in 2 groups of 7 divers and 2 divemasters. I was in the second group, going in 15 minutes after the first as instructed. Four Brits in my group, all in their 60s by the look of it, started ascent after some 5 minutes bottom time. Two others stayed a few minutes longer. I remained for the maximum allowed time of 15 minutes (as JJ) had instructed and started my ascent right away. Sam, the remaining divemaster, was literally 5m above me throughout and ascended with me intially. When we reached 10m, he gave me the OK signal and went across to the other line (remaining at the same depth as far as I could make out) to attaend to the second tank that was suspended there. I was doing my 10m stop adjacent to another tank suspended there but I had plenty of air myself (I was on a 15-litre steel tank starting at 230 bar). From that point I lost track of Sam till I reached the surface.

 

[Bonuss]

I just want to say that I really really appreciate this whole discussion (well most). This is a dive I would like to be able to do (safely) one day. As has been reinforced I had already planned to do Intro to Tec course, with a good instructor. (I enjoy the tec side discussions and planning, but don't plan to go full tec due to cost, time and my current location, but I can still plan like I am!).

This discussion reinforced my existing thoughts, and gave me quite a few more.

Thanks for sharing, particuarly the OP, as he didn't have to!

Bob in CO
We're our own best hope for a hero!

 

[vincent54]

Dusting of my Naui dive table it appears to stop at 130 feet. On the pre dive, how did everyone calculate their decompression times ? and did everyone agree on the same dive profile. I must have missed that portion of the thread, sorry. I'm the diver who does one dive a thousand times, so don't have any experience in the decompression dives.

 

[Edward3c]

My opinion is the boat captain is just a bus driver. They owe it to you to get you safely to and from the wreck. As a certified diver you are responsible for your own self. I am pretty sure they could not do these dives in the U.S. since we are such a nanny state with lawyers run amuck. The SFM is probably the most famous wreck in Truk. There is a large demand for this wreck. They give a thorough briefing and don't force anyone to do the dive. They have divemasters in the water with bailout gallore. I think they make a basic tech dive reasonably safe for all but the worst divers who I have seen them talk them out of doing the dive. So in my opinion the answer to your question about why they let single tank divers do the dive is market demand ($$$$) and as I stated earlier I think people today lack personal responsibility. Any dive training covers the limits of that training so when pne exceeds that training they are assuming the risk. I do not see how the bus driver is at fault. I think they go above and beyond.

In the UK any charter skipper is just providing transport to/from a dive site. Its up to the divers (individually or as a group) to ensure they are capable of doing the specified dive, and have the right equipment; therefore, no checking of qualifications etc.

The exception just might be if the dive operator owned the boat, but even then the default position is they are the ‘water-taxi’.

Kind regards

 

[The Diving Badger]

First thing I did after reading this post was check the BSAC Nitrox Tables.

The planned dive was off the tables. We use 1.4 ppo (which is becoming the accepted limit, not 1.6).

On air most divers start to get narked from 15m, but the individual doesn't notice the effect much before 30m. (The error when recording marine species starts at 15m.) so when diving to the ppo limit with a weak mix the effects of narcosis (24%) will happen.

At the depth of this dive I would have thought trimix would be a better gas, see here for BSAC courses so you can get trained for your next trip.

Kind regards

Do you not consider 1.4 to still be high? I am confused about your statement as this becoming the accepted limit as a pose to a resting decompression limit of 1.6, where is this the case?
Also why would the PPo2 effect END?

 

[Lorenzoid]

I just want to say that I really really appreciate this whole discussion (well most). This is a dive I would like to be able to do (safely) one day. As has been reinforced I had already planned to do Intro to Tec course, with a good instructor. (I enjoy the tec side discussions and planning, but don't plan to go full tec due to cost, time and my current location, but I can still plan like I am!). I started putting together stuff to sling a bottle this year for various situation. Personally, at Truk depths, I want reduntant everything (air, deco calcs, computer, mask, etc). (Cause, there's only one me, and my buddy!)

This discussion reinforced my existing thoughts, and gave me quite a few more.

Thanks for sharing, particuarly the OP, as he didn't have to!

Bob in CO
We're our own best hope for a hero!

That's been my line of thinking, too, as I've been following this thread. Truk is on my bucket list, and I've read articles stating that most of the sites can be done within recreational limits. (Not sure whether that was said about the San Francisco Maru specifically, but I've seen pics, and I'd love to dive it in a way that I actually get to see it.) What this thread educates me to is that there are dive operators in Truk who play fast and loose with the term "recreational limits." I now know that if I dive Truk, I will not book my trip until I have been trained to do tec dives of this sort and will book with an operator that specifically caters to divers with the proper training and equipment and understands their needs.

 

[openmindOW]

I had no specific buddy as such. We were made to dive in 2 groups of 7 divers and 2 divemasters. I was in the second group, going in 15 minutes after the first as instructed. Four Brits in my group, all in their 60s by the look of it, started ascent after some 5 minutes bottom time. Two others stayed a few minutes longer.

I wasn't there, so I won't judge it. But the organization does not sound as if was safe. for example, no assigned buddy teams.

Did the divemasers have doubles?