Live Aboard and Risk of DCS

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

dnhill

Contributor
Messages
183
Reaction score
0
Location
East Texas
Does anyone know of recent articles that discuss the relative risk of diving for a week on a land based vacation verses a liveaboard? It would seem that with diving throughout the day, risk would increase, but I am looking for documentation.

If this has been previously discussed many times, my search skills may need a refresher.

Thanks

dnhill
 
dnhill:
Does anyone know of recent articles that discuss the relative risk of diving for a week on a land based vacation verses a liveaboard? It would seem that with diving throughout the day, risk would increase, but I am looking for documentation.

If this has been previously discussed many times, my search skills may need a refresher.

Thanks

dnhill

The issues are very well known. The more you dive, the more nitrogen you suck up, and the greater the chance of DCS. I don't know what kind of documentation you are looking for, but the subject is covered in every openwater manual I've ever seen. Any search on decompression theory should keep you reading for a year or two.

Are you a diver?
 
MechDiver:
The issues are very well known. The more you dive, the more nitrogen you suck up, and the greater the chance of DCS. I don't know what kind of documentation you are looking for, but the subject is covered in every openwater manual I've ever seen. Any search on decompression theory should keep you reading for a year or two.

Are you a diver?

I think what his point is, is that after 6 hours by the tables, you have cleared any RNT in your body. So he is wondering if and why there would be an increased risk of DCS from multiday repetitive diving if you don't break your NDL in any one day since you would zero out by morning.

I think that's a valid question, and I'm curious if there is an answer to it as well. If I hit a very low pressure group, I'll still be totally clean again in only 5 or 6 hours. So why would repetitive days of diving increase my risk?
 
Wijbrandus:
I think what his point is, is that after 6 hours by the tables, you have cleared any RNT in your body. So he is wondering if and why there would be an increased risk of DCS from multiday repetitive diving if you don't break your NDL in any one day since you would zero out by morning.

I think that's a valid question, and I'm curious if there is an answer to it as well. If I hit a very low pressure group, I'll still be totally clean again in only 5 or 6 hours. So why would repetitive days of diving increase my risk?
And I think MechDivers point is that diving is diving...regardless of where you sleep...and that info should have been taught when a diver is certified.
 
So you are saying then that there is no risk for multiday diving since I'm safe once I've zero'd out by the PADI OW manual.

Thanks.
 
Wijbrandus:
So you are saying then that there is no risk for multiday diving since I'm safe once I've zero'd out by the PADI OW manual.

Thanks.
The only odd ball rules about repeative diving I have seen is for diving at Altitude.
 
JeffG:
And I think MechDivers point is that diving is diving...regardless of where you sleep...and that info should have been taught when a diver is certified.

Diving your butt off doesn't matter as to location, and yes, any OW diver should know that, hence my question at the end. And I was not trying to be mean. The whole question just struck me as being asked by someone totally unfamiliar with decompression. No offense meant.

I don't have alot of faith in standard tables for repetive dives. And no, I don't think you'll be clear 6 hours after doing multiple dives, unless they're all in an 8ft deep pool. Any good dive planning software should be able to show that.
Also, deco theory being exactly that, theory, implies there is alot still to be learned about why things happen.
 
Wijbrandus:
So you are saying then that there is no risk for multiday diving since I'm safe once I've zero'd out by the PADI OW manual.
No. Just because your PADI dive table gives you an RNT of 0 does not mean that your body has freed itself of excess nitrogen. In decompression theory they use the term compartments to describe different types of body tissu. Tissue in the fastest compartment absorbs and releases nitrogen the fastest and, conversely, tissue in the slowest compartment....

I don't have any stats on how long it takes to release excess nitrogen from slower tissue but I believe it is a matter of days. For single day diving, you are more concerned about fast tissue because it's hard to load up the slow tissue enough to be at risk. On a typical livaboard trip divers do 4-5 dives a day over multiple days. Since the slow tissue never gets the chance to release all the excess nitrogen it slowly builds up and becomes more of a concern. If you dive the same dives/profile on a non-livabord the issue is the same.

That's the way I understand it though I'm certainly no expert. I'm sure Dr. Deco can explaing it better.
 
Ok, that makes a bit more sense.

I really don't care about the location of where I'm diving, that was the original poster. However, I am going on a week long dedicated dive trip this fall, and if there is a concern about long term nitrogen buildup, I'd like to find out more about it. Even though I'm an "AOW" diver, I really haven't done a lot of research or learning on this. A weekend of five dives has been the extent of my repetitive dives. Also, I don't have any dive planning software to simulate what my nitrogen loading might be, that was something I thought I only needed if/when I ever moved into deco diving.

I hope Dr. Deco or someone with the brains to explain this to a novice might chime in and give me enough information so I don't put myself at risk.

The trip I am going on is to Roatan in Nov. I understand it is possible to do 30 dives in five days. If that's not a significant number of repetitive dives, I don't know what is. :wink:
 
DAN reports that the average DCI case had 5.3 dives in a series. They also show a very dramatic increase in DCI cases when 6 or more dives are done in a series.

I also note that most of the discussion in this thread is about nitrogen. However when doing multiday repetitive diving microbubbles become an issue. Although not proven it is speculated by many that they are responsible for a significant portion of the unexplained DCI cases.
 
https://www.shearwater.com/products/perdix-ai/

Back
Top Bottom