Shallow diving, is there a time limit.....

[Relics]

I do a bit of diving using an electric hookah system. At 10-15 feet I can dive until my air runs out. By the time I recharge my batteries, I'm back in the water again. The batteries about 3.5 hours bottom time with two people at this depth.
Relics

 

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[upstatejay]

if you are going up only one pressure group, i.e. you are stay at or less than 35 feet, and you come to the surface, you may remain underwater indefinitely. This is the reason that divers can stay in underwater hotels/habitats off the coast of FL for an overnight stay and not get narced.

If you are really, I mean really interested, do a search for pressure groups and a paper by Eric Baker P.E. He lays out all the math for you and it is math heavy. a website carrying his links to his papers is http://www.vbtech.org/refinfo.htm

S.A.F.E. (Safely Ascend From Every) Diving,
J~

 

[ScubaDude]

There is an issue here that is getting overlooked. Staying at shallow depths for extended periods of time is not a big deal in itself. What a diver does need to be aware of is that the nitrogen loading/absorption in the soft tissues of the body is occurring due to your extended stay. Again not a big deal by itself, however problems can arise from doing this and then following it with a deeper dive with the soft tissues preloaded with nitrogen. Your setting yourself up for something unpleasant if your not aware of it. Just because your shallow doesn't mean your immune to problems.

 

[jmohr]

The rule is round up to the next depth on the tables. Any dive under 35 feet is considered a dive at 35 feet. Sorry to bust your bubble.
If you disregard the tables you risk decompression sickness no matter how shallow the dive.

 

[grumpyolman]

The analogy that helped me understand why you exhale when going to shallower water is...
1. Blow up a ballon as full as you can get it at the end of the pool tie it off and jump in and take it to the bottom. It gets smaller because there is greater pressure in the water at depth than on the surface. You come back to the surface and it's the same size as when you filled it.
2. Take another ballon to the bottom of the pool and fill it from your scuba tank to the same diameter as you did the first one and tie it off, which would be like holding your breath, and head to the surface. Be sure to exhale here. The water pressure is less as you go up and at some point the ballon, your lungs, goes pop. Pink frothy blood everywhere and you better hope you have some paramedics and a hyperbaric chamber near.
Heard about a pool situation from a NAUI (don't have em around anymore I dont think) instructor where a beginning student was on the bottom of the shallow end 3' using the scuba for the first time. For reasons unknown the student paniced, held their breath and stood up as fast as they could to get to safety. They emoblized but lived through it. Thus the reason for the training. To teach you to do what'l keep you safe in an emergency situation. Jim

 

[mikep829]

Ok, I decided to chim in. I am and have been a Navy Diver for 12 years, in a since everyone here has been right, it all depends on what manual you look at. The Navy Dive manual pretty much gives us unlimited time at 30 ft. or less. It is pretty much impossible to get DCS at that depth, regardless of the time there. YES you can get AGE. When talking about diving, there is DCS type 1, DCS type 2, and AGE. The wife is waiting for me, so I must run, I will be happy to explain more later. Dive Safe,Mike!

 

[divewrecks]

Mel Fisher's wife "Deo", who passed away in January, set the womans record in the 1953 for duration underwater as a publicity stunt for Mel's shop in Redondo Beach, CA. She stayed underwater for 55 1/2 hours at a depth of 10 feet.

Stan

 

[rubberdiver13]

as long as you have air, you can dive all day.

yes he's right, i passed 3yrs ago, doing my master diver (padi) now, 3 dives left ,
as long as you keep shallow, until your down to 50bar, consulate the tables for your next dive, and surface time

 

[iClass]

Hey,
New member here. Enjoyed the thread. Surprised no one pulled out the Doppler No-Decompression limits table (based on the U.S. Navy Dive Tables).

Sorry to break it to y'all but for zero nitrogen to be absorbed at a depth of 10' you can stay in the water 60 mins or less. 15' 35 mins. 20' 25 mins. 25' 20 mins. 30' 15 mins. 35' 5 mins. Now this is not to say you cannot stay at depth longer. That is the time limit before your body starts retaining nitrogen.

For No Decompression dive time limits 20' and less show an unlimited time frame to be safe. 25' = 245 mins 30' = 205 mins 35' = 160 mins 40' = 130 mins 50' = 70 mins 60' = 50 mins

Best advice go to a refresher dive course either PADI, or SSI.

 

[JP]

Thanks again to all that replied.

What I decided to do was take the refresher course back in January 2009. I now am an Advanced Diver and have been averaging 4 dives per month. The plans are to take the Rescue Diver course next month and then when I reach the required number of dives go on to Master Scuba Diver.

I've been metal detecting at depth now and have found it is not an easy task. I follow the tables but use the dive computer more. The main thing is that I found out at shallower depths it's mostly dependent on your air supply, i.e. it will run out way before your bottom time does, plus the exhaustion of working in water.

Just remember all of those that are thinking about diving or using a Hookah system, if you are going underwater take a diving course. That's why I posted this originally because I was reading on the forum and other forums about those that were just buying Hookah systems or buying scuba and just going. Read in the DAN news about all the accidents just in 20 feet of water down here in Florida. A few of these accidents involve Hookah systems and I imagine they are from lung expansion injuries even though the articles do not state it.

Thanks again everybody and safe diving to all.

 

[Slugrusher]

Dive4it...

Bladder limit...how else are you supposed to warm up a bit?

 

[Oilfield Diver]

Every dive is a calculated risk, no matter what the depth is. Know your individual limitations, your equipment, and don't hang your "blessed assurance" over the edge too far or too often (preferably never). It is never worth it. There are an average of 40 commercial divers each year who would attest to that if they were still vertical. In the commercial deep sea construction field, company tables have a limit of 180 minutes for your depth question - whether it is 40 feet max or 1 feet max. Beyond that you are in recompression using oxygen territory. There are many factors to consider, physical health, body type, water temperature, type of work involved, equipment, etc. (I will spare you the myriad of potential complications that could occur). So, the companies I have worked for (which were known to be the best in the world) tables say for 1 feet of depth down to 40 feet of maximum dive depth, 180 minutes "maximum bottom time". If you exceed this time limit at all - by one second or more - the table requires surface decompression in a recompression chamber using oxygen - which I am pretty sure scuba divers don't carry around with them. Don't fool around, don't push the limits on depth or time. There you go scuba hunters.

"There are old divers and there are bold divers, but there are no old bold divers"..