OSTC SPORT. How can you compare conservatism levels?

[guyloup]

Hi, I am trying to find out the deco calculation that I would use for my own dives. Most of them are "semi advanced" recreational, this is max 42m and max 15 déco time. This is VERY far away from tek dives .

When I am simulating deco dives on the deco plan, using 115%/85% in Bülman or 20/75 in Buhlman + GF for a dive @ 28m for 30 minutes, the déco plan IS SO DIFFERENT THAT I HAVE A THOUGH TIME TO BELIEVE that the same conservatism scale was used. However in the OSTC sports, these are de défault for a +1 conservatism, as I can read from the manual on page 61.

On the single Bühlman one has 9'@ 3 m.
On the Buhlman with GF, one has: 1'@ 15m, 1'@ 12m, 3'@ 9m, 5'@ 6m and 13' 3m.

Now, I am not saying that one is right and the other is wrong, but I somehow have a problem that the conservatism level seems quite different in both deco plans.

Can anybody help me understand this discrepancy. I just cannot understand why these profiles are so different. I am, of course, not pointing at the "deep stops", this is what I want, but this is WAY OFF what I used to have in the past and what I see around me in recreational diving.

[heinrichsweikamp]

The two models are very different. The GF model results in a) much more deco and b) deeper stops.

Yes, 9min @ 3m seems to be a very aggressive (Short) deco compared to the GF deco plan, BUT that's the way this was used for decades in sports diving.

regards,
Matthias

[guyloup]

Since you claim that the OSTC SPORT is designed for recreational divers, one has to understand that only O2/N2 is used for these dives with rather small deco times. With Nitrogen as the leading gas, I believe that your choice of conservative CF looks a bit odd. Especially when one considers that the question of deep "deep stops" is still highly debatable. I would have preferred CF in the range of 60/80 (if not slightly more ) for neutral conservatism. But I understand that there are different schools. ::o

[max]

Hello. Probably you have already seen it yourself: in a previous thread beginning of Dec. (" Sport - gradient factor settings for conservatism" ), in which I asked about conservatism and GF settings for the Sport, Matthias replied "Maybe we add a "custom" conservatism where you can configure your own." Perhaps it will be implemented sooner rather than later if more people ask for it?

[guyloup]

Done as you suggested max (:P)