cave profiles..

[Mako Mark]

The problem states that you need a 20' stop by the time you reach point A. By the time you swim a considerable distance at a depth of 25' to point B, you've now spent a signficant time below your original stop. This in turn pushes you into a deco schedule calling for a 30' stop, but there is no place deep enough to do it.

QUOTE]

Ahh, this is a rounding error of the tables then right?

If you have desktop deco software and you changed the stop depth from 10 feet intervals to 5 feet intervals, it would give you a 25 ft stop instead of a 30 foot one. Right?

You still havent generated a stop deeper than your present depth, but your stop interval has rounded it to 30 ft.

would a dive computer do the same? or would it just extend the 20 ft obligation?

 

[MikeFerrara]

The problem states that you need a 20' stop by the time you reach point A. By the time you swim a considerable distance at a depth of 25' to point B, you've now spent a signficant time below your original stop. This in turn pushes you into a deco schedule calling for a 30' stop, but there is no place deep enough to do it.

QUOTE]

Ahh, this is a rounding error of the tables then right?

If you have desktop deco software and you changed the stop depth from 10 feet intervals to 5 feet intervals, it would give you a 25 ft stop instead of a 30 foot one. Right?

You still havent generated a stop deeper than your present depth, but your stop interval has rounded it to 30 ft.

would a dive computer do the same? or would it just extend the 20 ft obligation?

Using desk top software or a computer you avoid the problem. The issue only exists when planning with a table based on max depth and total bottom time.

the thought of going deeper to decompress is nuts. If you've been deep enough long enough to have a decompression obligation and you're at 25 feet you have been decompressing. LOL

 

[Mako Mark]

that is what I thought, I couldnt figure out how it was possible to ongas to a level deeper than you are, this is a mathematical problem not a decrompression problem.

Hey mike, are you following me?? lol

 

[MikeFerrara]

that is what I thought, I couldnt figure out how it was possible to ongas to a level deeper than you are, this is a mathematical problem not a decrompression problem.

Hey mike, are you following me?? lol

I sure am and as I said it's a problem that comes from trying to plan a multilevel dive as a squar profile at the maximum depth. As you said it's a math/planning problem and not a decompression problem.

 

[Duncan Price]

Do you folks end up with a lot of sawtooth profiles diving caves? I don't suppose the caves tend to naturally slope down and up in a diver friendly manner..? You must have to plan your routes to account for this.

It depends on the geology where you are diving. Caves tend to follow the lie of the rocks. In Florida a lot of the bedding is horizontal, thus you tend to descend between levels via shafts which makes for square profiles (or a combination thereof) which can be planned ahead using tables/software. Where the strata is inclined severely you tend to find caves with multiple saw tooth profiles and the diver has to ascend and decend mutiple times to traverse the passage (e.g the Gourneyras). This is difficult to model on most deco software and it is often expedient to employ a dive computer (or two) which will calculate one's deco on the fly. Often you will find that you have to do a stop before ascending one stretch of passage and then dropping back down the other side to a deeper depth again.

Duncan