Blindly trust computers?

[lowviz]

Whatever works for you. You are still waaaay ahead of the pack...

 

[CAPTAIN SINBAD]

Major communication gap between DIR and mainstream.

 

[lowviz]

Nice try.

Nope, this is basics. Just a scientific wild-ass guess will get you by...

 

[TMHeimer]

* Sigh * Those of us who actually understand this simple concept make simplifications to just get a SWAG as to what is reasonable. If the PDC falls anywhere close, then we happily go with that.

You are actually discussing 30' vs. 35'??? OK, so I see it as six and three-quarters hours to hit NDL on air at 30' vs. five hours to hit NDL at 35'.

Time spent there:

View attachment 494814

Not that it matters at this point, but my RDP says for 35 feet NDL is 205 minutes or 3 hrs./42 mins. approx.
Like dat Brooklyn sign -- it's freekin' good.

 

[letterboy]

Nice try.

Nope, this is basics. Just a scientific wild-ass guess will get you by...

What's your gradient factor of that swag?

 

[lowviz]

Uh, wait...

 

[BRT]

Whatever works for you. You are still waaaay ahead of the pack...

After this discussion I think you are doing what I might be able to do. Make an informed guess as to NDL's. It is not as simple as depth averaging. You have to have an idea what information to throw out and what to give more weight to. (Reverse profiles). I dive with people who do multiple deco dives in a day, day after day, with nothing but a watch or timer and a depth gauge. No tables, they know nothing about "60' for 60 minutes". They have just learned what works by feeling decompression signs and learning to avoid them. I know it can be done, but it is a disservice to newbies to act like you can just average depth and go by that.

 

[lowviz]

After this discussion I think you are doing what I might be able to do. Make an informed guess as to NDL's. It is not as simple as depth averaging. ...

This is the 'Basics' forum and, yeah, depth averaging works pretty well here. Most dives (here) are either (1) a square profile where the huge part of your dive is at similar depths with little to nothing in the shallows or (2) the profile is an 'out and back' following the bottom.

...//... I dive with people who do multiple deco dives in a day, day after day, with nothing but a watch or timer and a depth gauge. No tables, they know nothing about "60' for 60 minutes". They have just learned what works by feeling decompression signs and learning to avoid them. ...

You may wish to consider hanging out with MUCH safer people.

...//... I know it can be done, but it is a disservice to newbies to act like you can just average depth and go by that.

Most newbies get by with a dive computer and blind faith, no idea whatsoever of how long they can stay at the party.

Depth averaging (for newbie profiles) almost always errs on the side of safety.

 

[Ryan Mcshane]

They have just learned what works by feeling decompression signs and learning to avoid them. I know it can be done, but it is a disservice to newbies to act like you can just average depth and go by that.

As in - come up till it hurts?

 

[BRT]

As in - come up till it hurts?

More as in "if it hurts this time I'll decompress more next time".