Suunto Vyper vs Uwatec Galileo algorithm

[LowVizWiz]

It would be interesting to find out if there was any science upon which the extra penalty was based. Seems like it is just an arbitrary design decision.

Think about the reasons surface intervals exist and you have your answer.

If a diver has come close to the model's NDL the diver is still decompressing while being at the surface. Right?

For example, in the op's 51 minute first dive a 40 minute tissue compartment would be close to 60% saturated. So in a 40 minute SI that compartment will go to half it's current level of saturation or 30% and it will take another 40 minutes to drop to 15%.

For a that tissue compartment to be able to spend another 60 minutes under water the diver either needs to do a mandatory deco stop or do an SI of over an hour+

I over simplified the math, but the principle is there.
So to answer your question, no it is not arbitrary.

 

[KeithG]

Think about the reasons surface intervals exist and you have your answer.

If a diver has come close to the model's NDL the diver is still decompressing while being at the surface. Right?

For example, in the op's 51 minute first dive a 40 minute tissue compartment would be close to 60% saturated. So in a 40 minute SI that compartment will go to half it's current level of saturation or 30% and it will take another 40 minutes to drop to 15%.

For a that tissue compartment to be able to spend another 60 minutes under water the diver either needs to do a mandatory deco stop or do an SI of over an hour+

I over simplified the math, but the principle is there.
So to answer your question, no it is not arbitrary.

Sorry I did not make myself clear. I was looking for the science behind the "extra" arbitrary penalty that Sunnto applies if you "violate" its minimum 1 hour SI.

This extra penalty is why Hatul had 1 computer get bent well before the other computer was even close to NDL.

It is the extra penalty I was referring to, not the application of normal off gassing calculation.

 

[ianr33]

When I got back to my room I looked up the "Er" display in the manual and realized the Vyper was finished for the rest of the vacation.

-

Removing the batteries briefly should reset it.

Of course it will then consider your N2 loading to be zero,so be careful if you do that.

 

[LowVizWiz]

Sorry I did not make myself clear. I was looking for the science behind the "extra" arbitrary penalty that Sunnto applies if you "violate" its minimum 1 hour SI.

This extra penalty is why Hatul had 1 computer get bent well before the other computer was even close to NDL.

It is the extra penalty I was referring to, not the application of normal off gassing calculation.

I understood what you meant and the penalty (penalty isn't really the right word, but warning would be more appropriate) as I said, is based on SI off gassing calculations.

If you enter the water before 1 hour after the computer model places you at the edge of the NDL the "Diver Attention" icon will flash on the Dive computer itself and the manual states that the computer wants you to extend your SI. Sort of how PADI dive tables want you to have at least 1 hour SI if your ending pressure group is W or X on repetitive dives. This is the icon Hatul is referring to on his second post and it's a warning not a penalty

I've had the icon appear with as much as a 55 minute long SI
Here's a similar dive to the op's second dive after a deep dive in Coz


Now, where's the dead horse?