Narcosis

[DannyB]

On Sat morning dived the Seaford Ferry, max depth 51M. Diving CCR with 18/30 and a setpoint of 1.3

I work that out as an END of 29M, almost bath depth!

However....

End of dive get reel and SMB out, have new line on it thanks to kent tooling when re-lining the reel friday night I know I tied the caribena (sp?) on with a bowline, however for some reason I had a caribena on the SMB, and line on the reel, no connection.

I tried to re-tie the knot underwater, could I do it, could I heck! I am a scout leader and have been teaching the bowline for many years, on the surface (I've now done it several times to prove it to myself!) I can tie the thing blindfold. On the bottom, END 29M nope :-(

Fortunately my buddy (thanks Nigel!) managed to tie the thing so we ascended and deco'd our hearts out....

Is it me or is 29M a little shallow to forget simple things like this?

Danny

[Juz]

Was your mix defo 18/30?

Did you try other knots?

Were you aware that you were struggling?

How built up are you for a 51m dive?

Were you task loaded?

ETC ETC ETC


And of course, what's your narcosis tolerance like normally?

Juz

[DannyB]

Originally Posted by Juz

Was your mix defo 18/30?

Did you try other knots?

Were you aware that you were struggling?

How built up are you for a 51m dive?

Were you task loaded?

ETC ETC ETC


And of course, what's your narcosis tolerance like normally?

Juz

It was 18/30 or close to it.

Tried a figure of 8 but got well confused!

Knew I couldn't do it, knew where people normally go wrong (loop the wrong way round) checked it very, very carefully still couldn't do it not worried about it, just hacked off with myself and confused!

Reasonably built up, not perfect, but done several at similar depths in the last couple of months.

Normally get narced, won't dive air below 35M

Danny

[Juz]

Originally Posted by DannyB

Is it me or is 29M a little shallow to forget simple things like this?

Short answer is no, Narcosis differs day by day.

I'm with you, I'd be a little pissed off with myself, but then on CCR it's no drama to have an END of 25m on all future dives, let's be honest, difference in the gas cost is negligible.

Juz

[Rob Dobson]

I know I've posted this link before, but according to Mark Andrews (world record holder for diving on air) *most* if not *all* divers will suffer from narcosis @ 30m:

http://www.divernet.com/technique/10000narked.htm

I guess we just normally don't notice...

[divegyrl]

I know that my narcosis kicks in at 25-27m, at least it did at Easter when it was cold, dark and I had rocketed down the line after my buddy!
The sensus pro readout shows my rather impressive wibble waiting for my buddy to realise I wasn't there and come back!

I get the paranoid ones, so I always know when it happens, sometimes I can talk myself out of it, other times I just want out!

I did get quite narked on the Pottery wreck last week, my guess is that my 'poor mans mix' (20/20) wasn't up to the depth (55m) & my narcosis level! But it was bright, over 10m viz and relatively warm, so I just got the fuzzy, not doing things perfectly feeling, but I did know I wasn't right & called the dive

& I was on O/C so totally different from you YBOD boys!

[Mark Chase]

If I am planning anything interesting I plan an END of 25m MAX. 30 is plenty deep enough for Narcosis to slow you down in the UK. I even had a big narcosis hit in the red sea on an END of 35m on an 80m wall dive. All it took to bring this on was the stress of trying to dive a rig that was determined to invert me.



ATB


Mark Chase

[Twinsetmad]

Hi, I get narked at around 30m sometimes a bit deeper but not much...It makes me feel alot beter that someone else won't dive air below 35m. The deepest I've been is 44m and that was enough for me. I tried using nitrox to its max depth to ease the narcosis but it doesn't help much. I too get that paranoid feeling and want to get out. I have only ever had one time where I felt euforic..

I will be doing a normoxic trimix course next summer and I'm sure that will sort me out.

[nigelH]

Originally Posted by DannyB

Fortunately my buddy (thanks Nigel!) managed to tie the thing so we ascended and deco'd our hearts out....

*Shrug*

It was nice and light but it was thin line in thick gloves.
I was on 18/40 so head at 20m.
Payback time came when you were clear and I still had 4 minutes. You pay for the extra 10% of helium. Nice wreck, more broken than the description but not in the guide books and, more significantly, not in the reference book.

[Depth-junkie]

Same here, all ways plan my uk mix dives with a max END of 25m.
the difference between a 18/30 mix to a 18/40 mix is minimal in costs really in the long scheme of things, and i always find my dives a lot more comfortable and enjoyable with a lower end.

I once did a 65m dive on a 18/30 and did not enjoy the dive as i was narced pretty bad, it was dark and cold. Have also done the same dive on a 18/45 mix and it was a total different dive.