Can you dive all day under 20'

[bgtruk21]

Sorry if this is a rookie question, but I just finished my SDI on-line training and one of my questions wasn't answered. My open water test isn't for another month and will probably be answered then but I can't wait.
A few years ago I went lobster diving with some guys, We went down 3 different times and spent about 45 min in a max of 20'.
They told me that you can dive all day at this depth without decompression sickness.
I tried to figure out these charts, but they didn't seem like they went that shallow. So basically what I'm asking is were they crazy or is there truth to this?

 

[Dsix36]

You can stay down at 20' as long as you have the air to breathe. After a couple of months there might be some possibility of needing some decompression.

 

[Scuba_Jenny]

Not crazy at all. Where I beach dive, it's not uncommon to do a two hour dive in under 20', switch tanks and go back out. You will get tired though, and sleep well that night.

 

[chrpai]

I would suggest learning the "book answer" before thinking outside the box with a real world answer.

For example, if I was doing O/W training with PADI and a test or instructor asked "how long can you stay down for @20'?" the "book answer" would be 205 minutes. (PADI requires 20' dives to be rounded to 35' for conservatism. ) More with surface interval credits of course.

As I understand SDI training you'll use your computer. So go ahead and give me the book answer per 'your' training.

 

[Akimbo]

All day, week, month, year. Full saturation, no problem. Breath a little oxygen before leaving bottom and you can do the same a 33'.

 

[bgtruk21]

Awesome, thanks for y'alls help. I thought I did here them talking about 33'. And yes I sure will give the "safe" answer when it comes time.

 

[TMHeimer]

I can't remember exactly, but I read somewhere that it is either 18' or 22' where you can stay down indefinately and make a direct ascent.

 

[Rich Keller]

You can stay all day at 20'. When I was doing bridge reconstruction we would do a 3-4 hour dive like that in the morning, come up for lunch and do another 3-4 hour dive like that in the afternoon.

 

[redacted]

but you do still need to pay attention to altitude adjustments and flying after diving.

 

[vladimir]

I tried to figure out these charts, but they didn't seem like they went that shallow.

And now you know why.