Surface interval

[Walter]

Did you take a PADI class after 1988?

 

[H2Andy]

oh yeah... 2001

 

[Walter]

That would explain it. Look at some other tables.

 

[in_cavediver]

No such possibility exists in any tables I would trust.

Why? Depending on the model used, you can account for the time at 0ft in the on-gassing/off-gassing. (thinking haldanian tissue models, Ignoring the models who have different surface off-gassing tissue rates than the on-gassing rates) It won't be much different but there is a measurable amount of off-gassing.

 

[Walter]

Because I'm aware of only one such table and it is way too liberal for me to consider it safe. The damned thing says you're clear on N2 after only 6 hours. The thing is scary!

 

[in_cavediver]

Because I'm aware of only one such table and it is way too liberal for me to consider it safe. The damned thing says you're clear on N2 after only 6 hours. The thing is scary!

Ah, I see know and I agree, 6 hours seems kinda short but depending on the rest of the model, it may be accurate. I have a set of buelhman tables that fit the bill (24 hour to N2 clear) as well as the custom tables I have cut. Mind you, I am not saying it's wise to do that type of dive, merely that the models out there of which some tables are based are not violated by such an action and can account for the time spent.

 

[Walter]

It is extremely short. They scare the hell out of me and will not use them.

 

[abamick]

SSI also teaches a minimum 10 min SI.

 

[sweatfrog]

Surface Interval is time on the surface, between dives. If it's less than 10 minutes you factor it as one continuous dive. If it's over 12 hours, it's a new diving day.

That comes from the Navy Diving Manual originally. Navy divers were tied into a single task parameter back then. With the advent of Doppler Systems, the technology has evolved/changed.

Because I'm aware of only one such table and it is way too liberal for me to consider it safe. The damned thing says you're clear on N2 after only 6 hours. The thing is scary!

That's part of the evolution/change of recreational diving and also one reason why there is more than one training agency out there. There have been no more divers bent using one table properly versus another according to DAN's statistics. The insurance companies wouldn't stand for it. Things would change faster than you could say "chamber".

 

[JRScuba]

Al hit it perfectly. If you floated on the surface between your dives, your instructor did you a disservice.

Hmmmmm?????

If you floated on the surface between dives, seems to me that is the same as if you were on a boat.

As long as the FLOAT time is the correct SI for the dive plan it would not matter whether you floated or was on a boat.