Oriskany Sunk Deeper: Safer or Not?

[Maverick]

130ft max has to do with the no decompression limit. onceyou go deeper than that the nitrogen build up so quick you are bound to get into deco and that requires special training

[60south]

130ft max has to do with the no decompression limit.

Hmm. I'm not sure I buy that.

According to the NOAA 1999 no-deco air table (or table of your choice) the NDLs for 130fsw and 140fsw are both 10 minutes, and 5 minutes at 150fsw. So why cut it off at 130? Using this table, you should be able to dive a square profile and hit the flight deck at 145fsw (rounded up to 150fsw) for, say, 4 minutes, then slowly ascending for the rest of the dive while staying within the NDL. Using a multi-level calculation or a computer should credit you for additional time on ascent, which may allow for a fairly lengthy dive despite the initial deep time.

Note that I am not necessarily arguing in favor of short deep dives, rather wondering where the 130ft depth limit comes from. Depending on the tables you use, there doesn't seem to be any obvious reason why 130 was chosen. Given a table that specifies NDLs to 140 or 150fsw, an experienced recreational diver might reasonably plan and execute a dive to those depths.

Risk starts going exponential with depth, but as far as I can tell no mysterious voodoo occurs at 130fsw.

http://www.ndc.noaa.gov/pdfs/NoDecoAirDiveTable.pdf

[Burntchef]

i'm pretty sure the oogie boogie man lives at 131fsw. thats why i allways carry my poking stick on deep dives, they hate the poking stick.

[Joshua Smith]

You're right- it's an arbitrary number. It's kind of like speed limits for cars: if you are the regulating agency, you have to draw a line somewhere. 140'? 150? 160'? You could probably do a bounce dive down to 160' in warm, clear water without picking up more deco than you could burn off on a nice, slow ascent. Hell, you could do deeper, I bet. But it's probably not a good idea. If you were in the business of certifying divers, with all the implied legal liability, where would you draw the imaginary line? Personally, if it was up to me, and I had a horse in the race, I'd say 100' was plenty deep for "Advanced Open Water Divers."

But I've broken most of the depth limits on the ten or eleven different cert cards I own. I agree, the rules are kind of silly, in a way. Is an Open water certified diver in great jeapordy if they do a dive to 65 fsw, when their c-card says they should only go to 60? Maybe. It depends on the diver and the dive.

The more I learn about diving, decompression theory, and accident analysis, the less cocky I get. I don't see touching the deck of the Big O as a serious risk for most single tank sport divers. But there are people doing it every week that probably shouldn't be diving in the first place, let alone pushing the NDLs and the recreational depth limits.

130ft max has to do with the no decompression limit.

Hmm. I'm not sure I buy that.

According to the NOAA 1999 no-deco air table (or table of your choice) the NDLs for 130fsw and 140fsw are both 10 minutes, and 5 minutes at 150fsw. So why cut it off at 130? Using this table, you should be able to dive a square profile and hit the flight deck at 145fsw (rounded up to 150fsw) for, say, 4 minutes, then slowly ascending for the rest of the dive while staying within the NDL. Using a multi-level calculation or a computer should credit you for additional time on ascent, which may allow for a fairly lengthy dive despite the initial deep time.

Note that I am not necessarily arguing in favor of short deep dives, rather wondering where the 130ft depth limit comes from. Depending on the tables you use, there doesn't seem to be any obvious reason why 130 was chosen. Given a table that specifies NDLs to 140 or 150fsw, an experienced recreational diver might reasonably plan and execute a dive to those depths.

Risk starts going exponential with depth, but as far as I can tell no mysterious voodoo occurs at 130fsw.

http://www.ndc.noaa.gov/pdfs/NoDecoAirDiveTable.pdf

[no excuses]

Just for a eye opener check out the old US Navy dive tables

http://home.flash.net/~table/table/p0000065.htm

Sweet 190' for 5 min. its on like donkey kong

well ok maybe not and the Navy divers might have been in better shape, younger, yadda yadda.
Oh yeh they also modified their tables since the good old days .

stan..

[CaptnJack]

Since there's no narcosis on the internet I'd monkey dive the Big O too, on air.

[Bric Martin]

I think that the divers here could put together a plan and then dive the plan. I wonder how many others would just follow along? It's all good, right up until it isn't!

I vote no.