Question Are frequent ascents and descents in shallow water (up to 6 metres deep) harmful?

[mouka]

Hi everyone, I plan to dive in a swimming pool with 6 meters deep just near my city. I'd like to practice some basic skills like negative buoyant descent, controlled emergent ascent and SMB usage, etc. So I probably need to ascend or descend very frequently. Are there any other effects on my body, like increasing the risk of DCS, except for ear balancing issues?

Thanks!

 

[lowwall]

No DCS risk. There is of course the usual embolism risk if you fail to keep an open airway during your ascents.

You will need to be conscious of properly equalizing on your descents. If you get a headache or other sinus aches then maybe take a break or call it a day. I'll suggest doing a little buoyancy control practice or other drills where you stay at one level for a bit after each descent so you aren't yo-yoing the whole time.

 

[TMHeimer]

The majority of my dives have been in 15-30 feet (1.5-10 metres) over the last few years. I probably ascended 5 or so times each dive to check exact location. No problems.

 

[elgringoperdido]

We go "bottle hunting" in Chesapeake Bay sometimes. There's a spot just off Havre de Grace, Maryland, that was a dumping ground for about a hundred years. Now it's a collection spot for divers looking for antiques, especially old glass bottles. Maximum depth is about 6 meters. I tend to surface about 20 times during a 60-minute dive to get my bearings, because the water is murky. The instructor who organizes the trips says there's no harm as long as we exhale on the ascent.

 

[OTF]

The research on "sawtooth" dives is limited, and any physiological implications are poorly understood compared to regular profiles. Computers and tables don't account for it well. However, lots of people do them and aren't dropping dead so it's not like you're going to get bent messing around in the pool.

Anecdotally, I feel an unexpectedly high level of fatigue (possibly an early/mild DCS symptom) after doing multiple repeat ascents from 6-10m depths. Many other working divers and instructors who do this frequently will report small abnormalities.

Doing very slow ascents, adding a safety stop, and using nitrox are all ways to mitigate potential issues. I wouldn't worry about it too much just practicing in a pool. Ascend slow, equalize frequently on the way down, don't hold your breath on the way up. Have fun. Extra pool practice is one of the best ways to become a great diver.

 

[happy-diver]

Nah mate diving not in a pool in conditions foreign to you is the best way to become a great diver​

 

[DiveLikeAMuppet]

Your ears might be unhappy. Last few meters the surface is the largest pressure gradient.

 

[Pearlman]

Your ears might be unhappy. Last few meters the surface is the largest pressure gradient.

That’s only relative to diving deeper like 20-30 metres right? If you never go deeper then it’s meaningless I suppose …

 

[johndiver999]

The research on "sawtooth" dives is limited, and any physiological implications are poorly understood compared to regular profiles. Computers and tables don't account for it well. However, lots of people do them and aren't dropping dead so it's not like you're going to get bent messing around in the pool.

Anecdotally, I feel an unexpectedly high level of fatigue (possibly an early/mild DCS symptom) after doing multiple repeat ascents from 6-10m depths. Many other working divers and instructors who do this frequently will report small abnormalities.

Doing very slow ascents, adding a safety stop, and using nitrox are all ways to mitigate potential issues. I wouldn't worry about it too much just practicing in a pool. Ascend slow, equalize frequently on the way down, don't hold your breath on the way up. Have fun. Extra pool practice is one of the best ways to become a great diver.

So your advice is to do safety stops when ascending in a 12 ft pool?

 

[boulderjohn]

Research on saturation divers shows that if all tissues are fully saturated at a depth of 20 feet or less, the diver can safely surface.