Is 130 ft too deep?

[scubacoz22]

No, it was not safe.

A 160 foot dive is a decompression dive, if you did this on air without training you were in more jeopardy than you know. Gas management is important BECAUSE you need to account for a major failure and still get out safely.

I do not have v-planner available to me at this time, so I have not run the profile. Did you head directly to shallower depths and eventually the surface after the blowout or did you continue to look at the pretty fishes at 160 feet for a while before heading up?

If you had a major equipment failure like a blown high pressure hose on this dive you should have been happy to get back to the surface even if you started back up immediately. If your dive master continued the dive (to look at the pretty fishes) with your backgas depleted and only after the long continuation of the dive did you head for the surface, you should have gone out and immediately bought a lottery ticket. I think you do not know how lucky you, and the other divers in your party were, because they were at risk too.

One important role of gas management is to have enough gas to safely get back to the surface if you have a complete failure at the most critical part of the dive. It is expected on a dive like yours with a major failure like yours the dive is over, period.

Yikes, this thread is starting to scare me.

Mark Vlahos

No we did not continue to look at the fishes i wanted to go up she said to hold on and we gradually went up to shallower depths. but dove normally instead of going up played around at around 80 for a short time and then 60, 40 etc. We did do a 15 min safety stop at 15 feet. I would agree that we should of ended the dive, and was very surprised that we had not. It was very scarey. Something I never want to do again thats for sure. BTW that was back in 1999 in Cozumel with Aldora,tHAT WAS THE first time i had dove that deep, my last deep dive before that was 120 ft. but 160 is scarey.
Kathy

 

[Daryl Morse]

No we did not continue to look at the fishes i wanted to go up she said to hold on and we gradually went up to shallower depths. but dove normally instead of going up played around at around 80 for a short time and then 60, 40 etc. We did do a 15 min safety stop at 15 feet. I would agree that we should of ended the dive, and was very surprised that we had not. It was very scarey. Something I never want to do again thats for sure. BTW that was back in 1999 in Cozumel with Aldora,tHAT WAS THE first time i had dove that deep, my last deep dive before that was 120 ft. but 160 is scarey.
Kathy

Just for kicks, I looked at the US Navy Dive Table, since I don't have any other table that goes that deep. It calls for 0 minutes of decompression for 5 minutes of bottom time at 160 fsw with 5:20 minutes ascent time. For 10 minutes of bottom time, it calls for a 5 minute ascent to 10 fsw with 1 minute of decompression and 6:20 minutes of total ascent time.

I don't see how the air could have lasted that long. How much air was left?

That is one scarey story.

 

[Mark Vlahos]

No we did not continue to look at the fishes i wanted to go up she said to hold on and we gradually went up to shallower depths. but dove normally instead of going up played around at around 80 for a short time and then 60, 40 etc. We did do a 15 min safety stop at 15 feet. I would agree that we should of ended the dive, and was very surprised that we had not. It was very scarey. Something I never want to do again thats for sure. BTW that was back in 1999 in Cozumel with Aldora,tHAT WAS THE first time i had dove that deep, my last deep dive before that was 120 ft. but 160 is scarey.
Kathy

Kathy,

OK, I am a little more relaxed.

It sounds to me like your dive master did began a slow ascent to the surface. Your stop at 80 was a deep stop, personally I would have put this stop deeper, but it is a good thing at 80. The rest of the stops sound to me like decompression stops, even the ones at 60 feet. A slow ascent is good and stops along the way are required from the depth you reached. If your dive master had allowed you to ascend directly to the surface chances are good you would have gotten DCS.

It sounds like the actions of the dive master in the water were generally appropriate. The actions of the dive master before the dive however were entirely inappropriate. By taking you on this dive, even if there had not been any equipment failure, the dive master put you at risk. You lacked the training to be able to surface safely on your own, and it seems that the dive master did not explain just what was involved in the dive. Even if the dive was explained to you, without the training to fully appreciate the situation you were not equiped to make the key decisions about this dive. Wether you knew it or not this was a total "Trust Me" kind of dive.

Your actions during the dive were good. The fact that you did not panic reflects well on you, at that depth narcosis and the hose blowout could have turned bad really quickly, by staying calm you helped contain the problem, cudos to you.

This type of dive can be and is safely done all of the time, if you want to do these dives get some training like Advanced Nitrox, Decompression, and even Trimix*. All of these classes can help you gain understanding about the effects of deep diving and how to surface from these dives safely. Even if you never dive this type of dive, the training can be benificial for recreational diving.

Best of luck,

Mark Vlahos

* I have not taken any instruction in any breathing gas containing Helium yet, I plan to in the future but scheduling is a problem.
MV

 

[padiscubapro]

Hi all. My husband and I will be diving in Belize and staying on the Lighthouse atoll in December. One of the dives he is really looking forward to is the Blue Hole. It seems to be one of those once in a lifetime type of dives, but I am a bit nervous. I have done about 30 dives with the deepest around 115 ft. I really would hate to miss out on this opportunity (I doubt we will be back to Belize any time soon). But -- I promised myself I wouldn't take any significant chances diving (2 kids at home I really need to come back to!). Is this a risky dive????

Several things should always be considered before diving deep..
a) how much experience you have
B) how confortable you are in the water
C) how well you have practiced and how confortable you are with emergency procedures
d) what type of gear you are using.

On deep dives a redundant gas source is generally recommended, and the regs must be high performance regs, the deeper you go the worse regs in general will breath.

If you feel unconfortable about the dive you probabaly aren't ready

For each person their feeling how deep is deep varies.. 130 fsw is a pretty good recreational diver limit, having to bail out from that depth offers a relatively good chance of success.
For divers with the proper training 130 isn't that deep at all...
These days almost all of my diving is technical diving with a majority in the 200-300 ft range with occasional dives considerably deeper.. A simple mneumonic to remember is ATKEE - Attitude, training, Knowledge, experience, and Equipment.
The above applies to all dives.. each type of dive has things that must be learned and prepared for. I have seen how many of these follow me dives are run, I would never recommend any loved one I know to "trust" someone they aren;t familiar with or know the backround of..
Most of these show me dives go well, the difference is the
Guide prepared to take control of an emergency if it arises, DOes the guide have the proper gear to support a possible rescue.

Many time the "guide" wants you to stay closely with the group thi sprobably means that you WANTED to do 130, but end up following the leader to much deeper depths..

Narcosis is real and by 160 most divers are measurable impaired, experienced dives can generally manage this depth and deeper (on air) IF there skills are welll learned and part of their automatic reactions AND if they aren't presented with more than one trouble at a time..


My recommendation is that if you decide to do this dive have at least some form of independent gas supply.. a spare air doesn't count.. I would see if you could rent a pony bottle of at absolute minimum 19cf (unless you are paniced it should gallow a reasonable ascent) but more realistically 30cf.

 

[Mark Vlahos]

Just for kicks, I looked at the US Navy Dive Table, since I don't have any other table that goes that deep. It calls for 0 minutes of decompression for 5 minutes of bottom time at 160 fsw with 5:20 minutes ascent time. For 10 minutes of bottom time, it calls for a 5 minute ascent to 10 fsw with 1 minute of decompression and 6:20 minutes of total ascent time.

I don't see how the air could have lasted that long. How much air was left?

That is one scarey story.

Remember the US Navy dive tables were written for strong, healthy men, in their late teens or early tewnties, and there is an expectation that adequate surface support is available.

Mark Vlahos

 

[padiscubapro]

Remember the US Navy dive tables were written for strong, healthy men, in their late teens or early tewnties, and there is an expectation that adequate surface support is available.

Mark Vlahos

Navy table also use a single gas.. air for both bottom and decompression..

Better procedures are needed to lengthen the bottom time, shorten the deco and increase safety.. There are plenty of tables that appear more agressive than The Navy Tables but due to proper gas switches and porocedures are actually more conservative.

I can get away with 80 cuft of bottom gas plus a 40 cu ft bottle of 50% to do a dive to 50m (165fsw) for 30 minutes on the bottom and have plenty of gas to spare for emergencies..

On my CCR this same dive would be at least 60 minutes on the bottom....

 

[MASS-Diver]

I can get away with 80 cuft of bottom gas plus a 40 cu ft bottle of 50% to do a dive to 50m (165fsw) for 30 minutes on the bottom and have plenty of gas to spare for emergencies..
....

You are talking solo diving right? If you were to do this dive as a "safe" dive where you had enough gas for your buddy - that would not be enough gas. If you disagree lets see the numbers. Again, I could buy that only ise 80cu' of gas on the bottom, but to do the dive safely you would need allot more.

 

[Daryl Morse]

Remember the US Navy dive tables were written for strong, healthy men, in their late teens or early tewnties, and there is an expectation that adequate surface support is available.

I know that, but thanks for pointing it out.

 

[MikeFerrara]

I can get away with 80 cuft of bottom gas plus a 40 cu ft bottle of 50% to do a dive to 50m (165fsw) for 30 minutes on the bottom and have plenty of gas to spare for emergencies..

....

You're not saying that you would do that dive only carrying 80 cu ft are you? If you are, I'd like to see your gas plan.

With an RMV of 0.44 cu ft per minute you would suck the entire 80 cu ft on the bottom and that's without considering the use of any of the gas for ascent, decompression below 70 ft, any contingency gas or taking into account that you can't suck the tank completely empty.

 

[rjchandler]

Just for kicks, I looked at the US Navy Dive Table, since I don't have any other table that goes that deep. It calls for 0 minutes of decompression for 5 minutes of bottom time at 160 fsw with 5:20 minutes ascent time. For 10 minutes of bottom time, it calls for a 5 minute ascent to 10 fsw with 1 minute of decompression and 6:20 minutes of total ascent time.

I don't see how the air could have lasted that long. How much air was left?

That is one scarey story.

i recall aldora being famous for hp high capacity tanks