Decompression stop for shallow dives?

[DandyDon]

You are right if your putting air in to go up once the air starts to expand when the pressure decreases then yes your going to shoot to the surface like a missile.

I'll admit - I did that once, 200 dives ago. Shot up after starting an 80 foot ascent (at 5,000 feet elevation, adjusted to a 112 foot ascent). Boy, did I feel dumb. I was grateful to not be hurt.

Padi doesn't teach going back down, but some do, and I did - back to 15 feet for 5 minutes.

So, there Dave - I've admited a mistake, too...

 

[Robert Phillips]

Hey guys, doesn't the inflator hose double as a deflator hose? If people are taught to surface vertically, like most of you do, this is needed to vent as well as to inflate. Most people call it an inflator, but it doubles as both. Give the guy a break
As for the multiple ascents and descents: Bad idea. If you cant see your buddy or don't know how to use touch contact, you should call the dive and find another place to dive or do it another time. A successfull dive is one you come back from AND enjoy. Dive another day.
I went out this morning to dive with a buddy who is not one of my regular buddies and he forgot his fins, well there were two other divers in the water who I could have tried to catch up with, but I don't dive solo by choice so I sat it out and will dive later in the week. You need to know when to call a dive.
Dive safe.
Robb

 

[Curt Bowen]

Went diving yesterday, visibility was horrible. Was diving in a rock quarry a few hours after a heavy rain. Couldn't even see your own legs in the water. My dive partner and I would go down to about 20 or 30 feet, lose sight of each other, and then surface to find one another. Well this makes my dive computer go crazy. Keeps wanting me to stop at 15 feet for 3 minutes. This happened 7 or 8 times. Our deepest dive was to 42 feet for about 45 seconds.

So were we endangering ourselves by avoiding the decompression stop? I felt it was more dangerous to lose sight of my buddy. On one occasion my buddies Air 2 came lose and wrapped around his tank (so he had to do a swimming ascent). Our average depth for the dive was probably 20-30 feet.

I dont know what computer you were using, but I think I would take it back to the lake and throw it in the deepest part and buy a new one. Unless it was really beeping at you because your ascent was to fast?

You can dive to 42 feet for many hours before getting any place close to deco.

As for up and down (YO-YO) diving. Try to prevent this as much as possible. Normally I prefer to do one or two long dives instead of 3-5 short.

 

[DandyDon]

Hey guys, doesn't the inflator hose double as a deflator hose? If people are taught to surface vertically, like most of you do, this is needed to vent as well as to inflate. Most people call it an inflator, but it doubles as both. Give the guy a break

Yes sir, you're right, and I thought of that, but he said...

On one occasion my buddies Air 2 came lose and wrapped around his tank (so he had to do a swimming ascent). Our average depth for the dive was probably 20-30 feet.

I took that as saying his buddy opted for a swimming ascent (like we're supposed to do) as a second choice - since he couldn't inflate.

There's a story in Accidents about a similar dive condition that ended sadly... http://www.scubaboard.com/t60283.html

 

[DavidPT40]

We did pre-dive equipment check. The velcro on my buddy's jacket simply came undone, allowing his air2 to come undone.

A tether line would have been nice, but we didnt have one.

We were just diving for fun Blue Devil. Didnt know visibility was bad till we got to the quarry.

I've done a bit of searching, my buddy and I probably had relatively little nitrogen in our blood during our dive. No real danger, but unsafe behavior no doubt.

But overall the dive was good, because we gained some experience. People who dive in pool-like water all the time are the ones who are going to panic underwater.

 

[DavidPT40]

Curt Bowen, It kept starting a 3-minute timer for a 15 foot safety stop.

 

[Curt Bowen]

Curt Bowen, It kept starting a 3-minute timer for a 15 foot safety stop.

Its screwed up. I have never seen a computer start a 3 minutes safety stop from a 40 foot dive. Again, if mine did that I would use it as a paper weight for my desk and buy a new one.

 

[DandyDon]

Its screwed up. I have never seen a computer start a 3 minutes safety stop from a 40 foot dive. Again, if mine did that I would use it as a paper weight for my desk and buy a new one.

I was wondering what kind it is...?

And I wonder if all the repeated, frequent ascents & descents ticked it off...?

 

[BlueDevil]

But overall the dive was good, because we gained some experience. People who dive in pool-like water all the time are the ones who are going to panic underwater.

I remember doing a near zero viz dive not that long after doing my Open Water course and it was a great learning experience. We did however know what we were in for - we deliberately chose to dive when we knew the viz would be bad, and planned for it by taking a buddy line. An interesting dive - but not something i would choose to repeat!

 

[BlueDevil]

Its screwed up. I have never seen a computer start a 3 minutes safety stop from a 40 foot dive. Again, if mine did that I would use it as a paper weight for my desk and buy a new one.

This may well be the way the computer is intended to function. It is most likely "suggesting" a safety stop, rather than insisting that it be done. For example the Mares M1 RGBM computer does this. It will suggest a 3 min safety stop at a depth between about 3-5m for dives greater than 10m. Even if I do a 10 min safety stop at 6m it will still recommend a safety stop at 3-5m - of course I can simply choose to ignore it. It seems that the safety stop feature is simply programmed in for all dives greater than 10m and it does not take into account your ascent profile prior to getting to the safety stop depth.