YO-YO dive

[Willard]

Hi to anyone
first of all i sorry for my improper english, :dontgetit but I’m italian
and I’m not so confident with your language.
Anyway I try to formulate my question hoping that someone could help me.
I’m a professional photographer and a beginner diver. (owd)
I fell in love with this amazing world so I couldn’t resist to bring my camera with me, just for fun not for work. Considering my diving unexperience I always programm my dives in shallow water (max 10 – 15 mt) and for short time, always no deco and in safety. I thought.
Yes because during my dive I often vary depth, respecting the 10 mt/min speed, looking for a shot.
A friend told me that I was doing a so called Yo-Yo dive and that was very dangerous. I stopped immediately diving asking some expert friends, instructors and also a medical doctor for reassuring answers with the only result to confuse me even more.
Someone maintained that was a Yo-Yo dive and was very dangerous others that were was no problem cause the shallow depth and in no deco.
Please can you help me I quiver to restart diving.
Thank you anyone

CIAO
.. e complimenti :35: :35: :35: :35:

 

[knotical]

You communicated well, even though English is not your first language.

Your question is a good one, but I’m not sure anyone knows an exact answer.
I’m not a doctor, but will try to provide useful information.

All dives have some risk for decompression illness.
Changing depth by large amounts, often, and/or rapidly all increase risk.
Shallower depths and slow ascents reduce risk.
I have known divers who dive like you with no apparent problem.
Breathe continuously, try to keep your depth changes to a minimum, ascend even more slowly (perhaps 3-5 mt/min), and stay shallower in the second half of your dive.

Good luck.

 

[Mako Mark]

Yo, willard.... welcome to the board.

the more you ascend and descend, the more you increase the risk of DCS. Try to start your dive at the deepest part and slowly get shallower during the dive.

Slow ascents are critical too, especially near the surface.

 

[Stirling]

Considering my diving unexperience I always programm my dives in shallow water (max 10 – 15 mt) and for short time, always no deco and in safety. I thought. Yes because during my dive I often vary depth, respecting the 10 mt/min speed, looking for a shot. A friend told me that I was doing a so called Yo-Yo dive and that was very dangerous.

How much do you vary your depth, and how quickly up and down? Even in shallow water and doing no decompression dives, there is a greater risk of injury from repeated increasing and decreasing pressure. The more often you ascend and descend during one dive in shallow water, the less time there is between ascents, and the greater the difference in pressure from ascending and descending, and that is not a good idea.

Remember that the difference in pressure is greatest in the first 10 meters below the surface, so going up and down frequently in shallow water creates great differences in pressure in a short time. The problem with sudden and frequent changes in pressure is not only risk of decompression sickness, but also increased risk of embolism or other expansion injuries (to lungs, ears, sinuses, etc.) from being squeezed and released from pressure, and then squeezed again, etc.

If you want to look for more information about the risk of injury from "yo-yo" diving, it is also referred to as "sawtooth" diving or a "sawtooth profile." Sawtooth refers to the teeth (dente) or cutting edge of a saw (sega), because the profile of the dive looks like this: ^^^^^^^^^. You can find more information about it using either term, yo-yo or sawtooth.

It is best to dive without too many and frequent changes in depth; if you can do most of the dive without changing depth very much, and start with the deeper part of the dive while gradually moving to shallower water, that would be safer. If you must change depths to look for good photo opportunities, be very careful to always control your rate of ascent, and always be sure to spend several minutes at a safety stop before ending your dive.

And your English is very good, by the way - certainly much better than my Italian after 30 years of neglect! Ciao.

 

[pipedope]

When I was still working as a diver in Florida I did LOTS of very short dives, down and up, 3-5 meters depth, often dozens of them during a day with lots of physical work.

It was my job to get the work done and that is what it takes some times.

The risk is much less when you are far away from having a decompression stop obligation.
I would NOT do a yo-yo dive or a bounce dive after a deep dive due to the risk of forcing bubbles past the lungs.

The shallow dives with lots of depth changes do have an increased risk of embolism but if you keep your airway open it doesn't happen.

It is good to ask the question and understand the risk.

 

[Dr Deco]

Commercial divers working in shallow water will often perform dives such as you described. I am not aware that there has been any particular problem with this type of diving.

As mention above, the commercial divers only do these yo-yo dives and do not perform deep dives and then these shallow excursions.

 

[Willard]

How much do you vary your depth, and how quickly up and down? Even in shallow water and doing no decompression dives, there is a greater risk of injury from repeated increasing and decreasing pressure. The more often you ascend and descend during one dive in shallow water, the less time there is between ascents, and the greater the difference in pressure from ascending and descending, and that is not a good idea.

This is my fear i often vary my depth also of 50 %. Often I find myself for example at 6 mt from 12 mt looking for a shot without realizing it, you know if I were at 30 mt I will noticed if I ascended to 15 mt but in shallow water sometimes is difficult.
Fortunately this happens always in slow ascends, I seldom use bc vest while diving.
(I hope the verbs are right). :34: :confused1

Anyway thanks to all for the informations. :60: They really helped me especially the post of Pipedope. In effect my dive is similar to some commercial dives so this week i extended my research also in commercial dives sites and I found an interesting report about it.

http://www.hse.gov.uk/research/rrhtm/rr214.htm

I know that you are profi deep divers but it is very interesting.
It’s an amazing world also at 10 mt depth.
Thank you again
CIAOOOOOO