Can you do too much deco?

[scubaozy]

Looks like I'm out of luck -

Not the same documentary but bits and pieces of the same expedition ->
Concept is going down in the bell, CCRs attached to the outside holds and work at depth whole day and spend the rest of the time at the surface on a compressed living compartment. They are using commercial diver training facilities for the expedition.

Totally - but to train archaeologists all the way through commercial diving to sat diving level...

It is harder to train a sat diver to be an archeologist. Actually with the approach above, no extra training required.

 

[leadduck]

different idea: since you have a small group of divers repeating the exact same profile many times, why not bring a Doppler bubble monitor and record their bubble grades? That could be interesting for them to see, how does it relate to exertion at depth, and also to adjust the decompression strategy if necessary.

 

[RedSeaDiver2]

Not the same documentary but bits and pieces of the same expedition ->
Concept is going down in the bell, CCRs attached to the outside holds and work at depth whole day and spend the rest of the time at the surface on a compressed living compartment. They are using commercial diver training facilities for the expedition.

It is harder to train a sat diver to be an archeologist. Actually with the approach above, no extra training required.

Interesting concept - looks like it works well for them. I can't see us ever getting that level of support, however something that may work is having something similar to the Aquarius marine lab positioned at 20 metres/66 feet and then using rebreathers + scooters to travel to and from the wreck each dive. That would solve a lot of other problems too like rough weather above.

 

[RedSeaDiver2]

different idea: since you have a small group of divers repeating the exact same profile many times, why not bring a Doppler bubble monitor and record their bubble grades? That could be interesting for them to see, how does it relate to exertion at depth, and also to adjust the decompression strategy if necessary.

Good idea! Will look at getting one.

 

[Celt]

For working dives, there's a different traditional method that you may have a look at. The effect of workload is faster on-gassing at depth by better perfusion, which is similar to longer bottom time in a non-working dive. In the old tables you would read at 1.5x bottom time for working dives. So instead of guessing a reduced GF, you could enter a 1.5x longer bottom time into MultiDeco, e.g. for a 20min working dive calculate an ascent with 30min bottom time and your usual GF. Comparing that ascent to your other results with reduced GF will give you an idea what GF reduction is compatible with +50% faster on-gassing due to workload.

What workload would a diver have to do to justify a 50% increase of bottom time. I've not heard that before and I've worked underwater for years. Exactly how is it calculated.

 

[L13]

different idea: since you have a small group of divers repeating the exact same profile many times, why not bring a Doppler bubble monitor and record their bubble grades? That could be interesting for them to see, how does it relate to exertion at depth, and also to adjust the decompression strategy if necessary.

Collect the data in a scientific manner and give it to DAN!

 

[Trace Malinowski]

I may have been bent during 3 months of mostly decompression diving before I was certainly bent with permanent injuries. What you're doing sounds exciting. Given the length of the project and decompression requirements, keep a close watch for any strange feelings, aches, etc. There was a day mid-summer when I wish I could go back and call DAN and take a chamber ride or several. Assume any minor ill feeling could be a hit and proceed accordingly.

 

[RedSeaDiver2]

I may have been bent during 3 months of mostly decompression diving before I was certainly bent with permanent injuries. What you're doing sounds exciting. Given the length of the project and decompression requirements, keep a close watch for any strange feelings, aches, etc. There was a day mid-summer when I wish I could go back and call DAN and take a chamber ride or several. Assume any minor ill feeling could be a hit and proceed accordingly.

Indeed! Sorry to hear that you have had things go so wrong! The length of the project and the amount of decompression diving is the main reason for the three team rotation plan meaning that the time between the day 1 morning dive and day 2 afternoon dive will give a surface interval of about 26 hours, and then the dry day 3 means that each diver will then have a surface interval of about 40 hours before they do their day 1 morning dive again. Hopefully this combined with GF's of 30/60 will keep everyone safe, but you never know who has an undiscovered PFO waiting to rear its ugly head etc.

 

[RedSeaDiver2]

The length of the project and the amount of decompression diving is the main reason for the three team rotation plan meaning that the time between the day 1 morning dive and day 2 afternoon dive will give a surface interval of about 26 hours, and then the dry day 3 means that each diver will then have a surface interval of about 40 hours before they do their day 1 morning dive again. Hopefully this combined with GF's of 30/60 will keep everyone safe, but you never know who has an undiscovered PFO waiting to rear its ugly head etc.

One other thing this helps keep under control is OTU's too

 

[boulderjohn]

If you want a high of 60 then I would have a low of around 50 not 30.

I just scanned through this thread quickly, so I may have misunderstood. It seems to me that the one clear message you have received in this thread, including Tom's quoted here, is that you are planning your first stops too deep. As I read it, you do not respond to these clear warnings, but just keep saying that is what you will be doing.

Perhaps you will take a moment to 1) correct me if I misunderstood or 2) explain why you are so adamant about using such deep stops.