DCIEM v Suunto Vyper

[Mark Chase]

Originally Posted by TonyD

SWMBO is now limited to 15m EAD, if she wants to exceed this, use DCIEM air table.

She has a PFO, but has not been told to stop diving, but if she wishes to dive to use the above, this came from Dr P. Wilmshurst.

One of our group has a PFO and was doing 60-90m dives of up to three hours for several trouble free years.

The only answer I can think of as to why she got away with it was that she was diving enrixhed nitrox decompresion mixes.

I beleive she had the opp in January


That aside,

Tables are great if you folow the rules exactly but they fall down if the diver dosent do what he/ she is suposed to. I proved this to my self many times when running tables beside a VR3.

Asuming (if you'r using a vyper) you looking at max depth 35ish m dives I would introduce standard stops on the ascent reguardless of ceiling shown on the Vyper.

For a twin 12s air dive your bigist dive is likley to be 40mins at 35m, for which id start stops at 21m. For a more normal dive like 20mins at 35m I'd stop my fast ascent at 21m and do a 3m/min ascent to 9m. On a big dive like 40mins at 35m id use the 1,2,3,4,5 stop pattern

1 @ 21
2 @ 18
3 @ 15
4 @ 12
5 @ 9

Clear the Vyper at 6


This aproach needs planning as the time to surface on the Vyper will be rubbish till you get to 6m

The most critical phase in any deco is from 10 to the surface. Once you clear deco its best to spend 5mins getting from 6m to the surface. I do this and all my deco dives.

Ultimatly if you can get qualified for 02 then it would be safer still doing the 6m stop on pure 02 and using air tables.

If all that is too complicated consider getting a GF bassed dive computer like the Shearwater Pursuit. Set to 10/80 it will do all the above AND give you proper time to surface information.


ATB

Mark Chase

[gobfish1]

Deeper Into Diving, by John Lipman, has said tables in it along with other's

[EdHornby]

Earlier this year I did a trip to norway, with a fair bit of deco racked up on the dives, and I wasn't impressed with the vyper profiles.
I felt that the vyper wanted me straight out of the deep and fizz off at 5, then 4, then 3m - on one dive the tide and wieght of the divers had dragged the buoy on the shot from the surface to about 8m and the vyper wanted me at 4m so wasn't clearing, which considering I'd done manually calculated deep stops and sensible ascent times left me a little unimpressed to say the least..

(I had a side mount with 50% so cleared the rest of the stops when we bagged off quite safely)

If I was going to replace the vyper I'd look hard at the other options and get loaners where possible to see how they work in the water

[EdHornby]

aapologies - my last post was off topic, my apologies for not reading all details properly

I'd say that 32 on air tables will be ok, but a week in the red sea will be the best way to get back into it - fish, corals.... brilliant...