bl6394, is there a rule against teaching the BC as BC method in a PADI course? I'm not an instructor, nor have I taken the drysuit course, but I got the impression it was more of a recommendation than a requirement to teach it that way. Why not teach the way you dive (assuming PADI doesn't require it that way) and just use the course material to guide any questions and give full information?
Dry Suit and Buoyancy Control
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Dhboner
Contributor
I understand what you are saying and appreciate your logic but I cannot agree. Scuba instruction is essentially training in managing life support equipment in a potentially dangerous environment. If I did not wholeheartedly agree with my certifying agency's approach to any technique, I could not in all conscience continue to teach for that agency. I understand the agency's right to develop and promote their curriculum but if I felt it was not appropriate in all situations and if I felt it put a new diver at any risk I would do my homework and find an agency that better reflected my beliefs. Fortunately the core principles of most agencies are pretty close and there is general consensus for most techniques for teaching diving skills to new students but I believe that using a drysuit for primary buoyancy control is potentially dangerous to an inexperienced diver and could never teach that technique in good conscience.
Largely Risk Mitigation drives this choice. In the course, PADI specifies that the recommended technique is to have recreational divers in shell dry-suits use the dry-suit underwater to control their buoyancy. In the Instructor Manual - it is never explicitly stated that ONLY the drysuit may be used to control their buoyancy under water as I evaluate their completion of performance requirements. I could perhaps have them use the approach that PADI reserves for technical divers with my recreational students for controlling buoyancy with a drysuit.
However, if during the class the student experienced an injury that resulted in an incident report: for example - a freeflow that increased their task loading and resulted in an uncontrolled ascent where they became embolized. If I was not having them follow the recommended technique for managing their buoyancy - I would not be surprised if some training agency asserted that my imprudent choice to allow them to use other than a recommended technique contributed in some way to their injury.
Rather than risk that sort of debate - I teach the course using the recommended skiils. At the same time - I counsel the students as to the other choices they may make immediately after certification. At that point in time, they have learned how to manage their buoyancy with a drysuit, they previously understood how to manage their bouyancy with a BCD, and they have been reminded that their BEST option is to be properly weighted in a balanced rig - and do the fine tuning of their buoyancy control with breathing control - if Open Circuit.
---------- Post added January 13th, 2016 at 01:28 PM ----------
When I was doing my MSDT training, I was in a dry-suit with a side mount rig, two steel LP95's and a stage bottle... A Course Director insisted that I demonstrate the Deep Adventure Specialty Dive - while using the dry-suit as primary inflation. I was the Michelin Man with all that gas in the suit.
If you think that using a dry-suit for primary buoyancy control is potentially dangerous for students in an AL80, - try to do it with a steel twinset and a stage: descending to 65 feet, hovering neutrally buoyant while demonstrating skills, and then returning to the surface in a controlled manner.Yeah - I get what you're saying. We all do the best we can with things we can't control.
TONY CHANEY
Contributor
Just another point of view FWIW and I dive dry almost year round and much more than wet: As I descend I add gas to the BC for buoyancy and to the suit to offset the squeeze of the suit. At the bottom (or depth) the same still applies. When I start to ascend I start to open the dry suit valve until a few bubbles start to come out (not a total dump mind you). At this point the dry suit is almost self venting (works better with a neo. suit) as the gas inside the suit expands and I am now able to focus on just letting gas out of the BC. If you get ahead of the venting from the suit then you can dump faster from the BC thus preventing an uncontrolled ascent to the surface. It works for me.
On page 86 of the new SDI Drysuit manual there is a subheading in Chapter 7 on Diving the Dry Suit. This subheading is "Your Drysuit Is Not Your BCD!"
When I wrote the new manual and course that was a key point I wanted to make and SDI agreed with me.
That was old school thinking, and as others have alluded to, done with the idea that using the drysuit and BCD in conjunction with each other was too much task loading for a new drysuit diver. The fact is that in a proper course with a diver who has also had proper training in buoyancy control and trim as an open water diver, which all should have, it's not at all too much.
In fact as I stated in the manual, "a new drysuit diver is likely to vent the BC out of instinct", and "Keeping just enough air in the suit to offset squeeze and using the BCD for buoyancy ensures that there is less chance of excess air getting trapped in the suit that cannot be vented quickly in an emergency."
When I teach the drysuit course I do have students practice extensively with adding and venting air from the suit and the BC. Now one thing that can be done to show how to do this and have students adding enough air to actually see the results is to use extra weights to prevent uncontrolled ascents.
I know for me in the pool that I really don't need to put much air in the suit at all even with light undies to take off the squeeze. Especially with a well fitting suit. To get enough air in the suit to show more than a few bubbles coming out of the vent I need to add some extra weight.
This allows me to swim and demo the use of the inflator and vent without corking. Students find it helpful as well since they can practice with using both before we hit open water. There we will do additional weight checks and allow them to get the minimum amount they need. This way they are not over weighted and get to see early on how easy it really is to use both as necessary. With experience comes some realization that if you have your weighting nailed the amount of air you need to add to the suit is enough to get neutral and offset squeeze. To a point. At some point you can offset the squeeze but find that you still need a little extra air in the BC.
I find this on deep dives. I can offset the squeeze just fine but need some extra air in the wing. I could put it in the suit but then the risk of too large a bubble is unacceptable. Or with the new streamlined suits and more effective undies you don't need as much air in the suit to stay warm and offset the squeeze.
As I state on page 88 of the manual "It is NOT beyond the ability of the average, well trained, open water diver to manage adding air to the dry suit and the BCD."
When I wrote the new manual and course that was a key point I wanted to make and SDI agreed with me.
That was old school thinking, and as others have alluded to, done with the idea that using the drysuit and BCD in conjunction with each other was too much task loading for a new drysuit diver. The fact is that in a proper course with a diver who has also had proper training in buoyancy control and trim as an open water diver, which all should have, it's not at all too much.
In fact as I stated in the manual, "a new drysuit diver is likely to vent the BC out of instinct", and "Keeping just enough air in the suit to offset squeeze and using the BCD for buoyancy ensures that there is less chance of excess air getting trapped in the suit that cannot be vented quickly in an emergency."
When I teach the drysuit course I do have students practice extensively with adding and venting air from the suit and the BC. Now one thing that can be done to show how to do this and have students adding enough air to actually see the results is to use extra weights to prevent uncontrolled ascents.
I know for me in the pool that I really don't need to put much air in the suit at all even with light undies to take off the squeeze. Especially with a well fitting suit. To get enough air in the suit to show more than a few bubbles coming out of the vent I need to add some extra weight.
This allows me to swim and demo the use of the inflator and vent without corking. Students find it helpful as well since they can practice with using both before we hit open water. There we will do additional weight checks and allow them to get the minimum amount they need. This way they are not over weighted and get to see early on how easy it really is to use both as necessary. With experience comes some realization that if you have your weighting nailed the amount of air you need to add to the suit is enough to get neutral and offset squeeze. To a point. At some point you can offset the squeeze but find that you still need a little extra air in the BC.
I find this on deep dives. I can offset the squeeze just fine but need some extra air in the wing. I could put it in the suit but then the risk of too large a bubble is unacceptable. Or with the new streamlined suits and more effective undies you don't need as much air in the suit to stay warm and offset the squeeze.
As I state on page 88 of the manual "It is NOT beyond the ability of the average, well trained, open water diver to manage adding air to the dry suit and the BCD."
The course now specifically says that dry suit divers should use the buoyancy control system that allows them to achieve good trim and in water efficiency. Whether it's the BC, dry suit, or both and instructors are to teach that.
OP
coralreefer_1
Contributor
First, I want to thank everyone for the replies, knowledge and experience. I wrote a reply last night but it got removed (as well as many other back and forth discussions in this thread) with the upgrade.
To update and add a bit more information. My instructor never actually told me that I should use the dry suit for buoyancy. I took that information from a PADI video that I found on youtube ( a video I must admit is likely 15-20 years old). Since I live in S. Korea, and although I speak and understand Korean as a reasonably high level, I have always supplemented my in-class training and dive training with PADI videos I have found online. Of course I read the manuals but the videos were convenient as I could reply them over and over while sitting and actually watching, or otherwise cleaning or other odds and ends around the house. I cannot say enough how valuable those videos were when I began my OW training last year. They gave me basis for understanding stuff in Korean that was vocabulary I was not familiar with at that time.
Basically my in pool class consisted of little more than donning the suit, pivoting on the bottom, an exercise where I was to add and vent air simultaneously (which I believe was designed to demonstrate something touched on above to show that deflation rate is slower than the inflation rate, as this was where I had the uncontrolled ascent), a forward roll technique that I saw in the video as one of a few ways to slow ascent and bleed air in the case of rising too quickly, and demonstrations of removing and reequipping the scuba unit (which I failed at completely)
I made a video of it as a first entry to a new video blog I am beginning. Its all in Korean, but I did it to see myself from an instructors perspective to see the things I was doing wrong and how to improve. Anyone interested can see the video here.
I was pretty bummed and somewhat worried after my first post, as I knew then that I would be doing open water dives the following weekend (tomorrow at the time of this post). After reading all that was written here ( as well as those that were deleted) I feel much better. In my heart I wanted to use the dry suit for buoyancy because that was the class and specialization I was taking, and since the video said as much, I was kind of on a mission to demonstrate that in an effort to "deserve" the certification. That still may or may not be true, but the general consensus of the posts amounted to " Do what you are comfortable with). Since our open water dived are usually to 25-30 meters, I feel much better going to bed tonight that I am "allowed" so to speak to rely or even use my BCD (As the video basically said the BCD was only for buoyancy at the surface)
I will update this tomorrow just to put it out there how it all went, and the second entry on the vblog will cover the dives tomorrow. Until then, thanks again for the awesome input and community support!
To update and add a bit more information. My instructor never actually told me that I should use the dry suit for buoyancy. I took that information from a PADI video that I found on youtube ( a video I must admit is likely 15-20 years old). Since I live in S. Korea, and although I speak and understand Korean as a reasonably high level, I have always supplemented my in-class training and dive training with PADI videos I have found online. Of course I read the manuals but the videos were convenient as I could reply them over and over while sitting and actually watching, or otherwise cleaning or other odds and ends around the house. I cannot say enough how valuable those videos were when I began my OW training last year. They gave me basis for understanding stuff in Korean that was vocabulary I was not familiar with at that time.
Basically my in pool class consisted of little more than donning the suit, pivoting on the bottom, an exercise where I was to add and vent air simultaneously (which I believe was designed to demonstrate something touched on above to show that deflation rate is slower than the inflation rate, as this was where I had the uncontrolled ascent), a forward roll technique that I saw in the video as one of a few ways to slow ascent and bleed air in the case of rising too quickly, and demonstrations of removing and reequipping the scuba unit (which I failed at completely)
I made a video of it as a first entry to a new video blog I am beginning. Its all in Korean, but I did it to see myself from an instructors perspective to see the things I was doing wrong and how to improve. Anyone interested can see the video here.
I was pretty bummed and somewhat worried after my first post, as I knew then that I would be doing open water dives the following weekend (tomorrow at the time of this post). After reading all that was written here ( as well as those that were deleted) I feel much better. In my heart I wanted to use the dry suit for buoyancy because that was the class and specialization I was taking, and since the video said as much, I was kind of on a mission to demonstrate that in an effort to "deserve" the certification. That still may or may not be true, but the general consensus of the posts amounted to " Do what you are comfortable with). Since our open water dived are usually to 25-30 meters, I feel much better going to bed tonight that I am "allowed" so to speak to rely or even use my BCD (As the video basically said the BCD was only for buoyancy at the surface)
I will update this tomorrow just to put it out there how it all went, and the second entry on the vblog will cover the dives tomorrow. Until then, thanks again for the awesome input and community support!
OP
coralreefer_1
Contributor
Update as I said I would: - Had my two open water dives today. It was a mixedbag to say the least.
First let me say that diving with the group/resort my instructor takes me to is a wild experience. Diving in Korea is more or less about people catching something to supply/sell to restaurants or for consumption. Even with Jeju Island being one of the few spots Korea can claim as even passing as decent diving compared to the rest of the world, its just an adventure. My only experience (13 logged dives to date) have all been with the same outfit and I can only imagine what some (or most) of the more experienced people here would think of it. Fumbling onto a flay bottom boat with fishing spears by nearly everyone exept me lying around on the narrow walking space...I fear for my life every time i board or depart that vessel. UImust admit though, as dangerous and lacking in safety as they are...Koreans (the ones i dive with are all old, 40-50 year old guys) are a hardy and jovial bunch...and remind me more of the dwarves from LOTR than anything else (and not because they are short because they are all bigger than me)
The diving began around 10am,with water temps about 12c. Upon entry I could not submerge no matter what, and had to basically be pulled down by my instructor. Once down the dive itself went fine, and we dove do 24 meters. Upon ascent though, I lost buoyancy control around the 1o meter mark. My BCD was empty and I was trying to relieve the dry suit, but apparently I was doing it wrong. I rose steadily from 10-12 meters to the surface with no control. Upon exiting the water my instructor mentioned we needed to add more weight. I am 70 kg and typically wear 8kg in a wet suit, but with dry suit last week we upped it to 10kg on the belt and two 0.5 weights on the ankles bringing me to 11kg. After the first dive today, we (or I should say he and the DV/captain decided I needed an additional 2kg)
During the break and upon my inquisition told me that when i was raising my left arm to release air,I was not tucking my right arm in. I was taught to raise the left ( thats where the release is) lean to once side, and tuck the right arm to squeeze out air...but I was not tucking the right arm in which apparently left a pocket of air I could not compensate for.
During the break I spent the 1.5 hours practicing this. I must have looked weird to the people there walking around the camp.
The second dive seemed to go much better. I do believe the extra weight was too much (maybe 1kg extra would have been better) as I sank to the bottom like a rock, and took me a good 3-4 minutes once at bottom to get my buoyancy right. After the first dive and that mishap,I endured one hell of a squeeze as I was afraid to put anything more than a tiny tiny bit of air in the suit.
The second dive though, I had a rather serious leak,and actually ended up signaling to my instructor that I was cold and we cut the dive short with over 1/3 of my air left. When i signaled I had 80psi (started with 215) but by the time we were nearing the surface I was almost completely empty. I'm not sure if the cold was causing me to to consume so much, as I wasn't really panicked but perhaps the stress of ascent (with the previous dives' uncontrolled ascent still hot on my mind,and maybe the cold) but anyway by the time we got to the surface (after a very short safety stop) I barely had any air...and my undergarments were soaked through.
To end my comments in this thread. I am not liking dry suit diving very much. However all of these experiences just drive me to work at it more and more. Originally the only reason I was interested in the dry suit specialty was because I wanted to start the rescue diver course right away after finishing my EFR, but I was told that I couldn't do that until spring unless I had a dry suit specialty. (and i didn't want to sit around for months with no diving experiences at all) Looking back, and considering the issues I had had with the dry suits,I do not want to do a rescue course in dry suits (although practice in those things with dry shell would only help to round out rescue training)
At this point, I finished the course and didn't die...so I guess that will earn me a certificate. With that said, I do believe I will arrange for instructor assisted non-curricular free dives to get in the ocean again with that dry suit to improve on my last finish. I don't want that certification until I feel confident that i can control myself in that suit.
First let me say that diving with the group/resort my instructor takes me to is a wild experience. Diving in Korea is more or less about people catching something to supply/sell to restaurants or for consumption. Even with Jeju Island being one of the few spots Korea can claim as even passing as decent diving compared to the rest of the world, its just an adventure. My only experience (13 logged dives to date) have all been with the same outfit and I can only imagine what some (or most) of the more experienced people here would think of it. Fumbling onto a flay bottom boat with fishing spears by nearly everyone exept me lying around on the narrow walking space...I fear for my life every time i board or depart that vessel. UImust admit though, as dangerous and lacking in safety as they are...Koreans (the ones i dive with are all old, 40-50 year old guys) are a hardy and jovial bunch...and remind me more of the dwarves from LOTR than anything else (and not because they are short because they are all bigger than me)
The diving began around 10am,with water temps about 12c. Upon entry I could not submerge no matter what, and had to basically be pulled down by my instructor. Once down the dive itself went fine, and we dove do 24 meters. Upon ascent though, I lost buoyancy control around the 1o meter mark. My BCD was empty and I was trying to relieve the dry suit, but apparently I was doing it wrong. I rose steadily from 10-12 meters to the surface with no control. Upon exiting the water my instructor mentioned we needed to add more weight. I am 70 kg and typically wear 8kg in a wet suit, but with dry suit last week we upped it to 10kg on the belt and two 0.5 weights on the ankles bringing me to 11kg. After the first dive today, we (or I should say he and the DV/captain decided I needed an additional 2kg)
During the break and upon my inquisition told me that when i was raising my left arm to release air,I was not tucking my right arm in. I was taught to raise the left ( thats where the release is) lean to once side, and tuck the right arm to squeeze out air...but I was not tucking the right arm in which apparently left a pocket of air I could not compensate for.
During the break I spent the 1.5 hours practicing this. I must have looked weird to the people there walking around the camp.
The second dive seemed to go much better. I do believe the extra weight was too much (maybe 1kg extra would have been better) as I sank to the bottom like a rock, and took me a good 3-4 minutes once at bottom to get my buoyancy right. After the first dive and that mishap,I endured one hell of a squeeze as I was afraid to put anything more than a tiny tiny bit of air in the suit.
The second dive though, I had a rather serious leak,and actually ended up signaling to my instructor that I was cold and we cut the dive short with over 1/3 of my air left. When i signaled I had 80psi (started with 215) but by the time we were nearing the surface I was almost completely empty. I'm not sure if the cold was causing me to to consume so much, as I wasn't really panicked but perhaps the stress of ascent (with the previous dives' uncontrolled ascent still hot on my mind,and maybe the cold) but anyway by the time we got to the surface (after a very short safety stop) I barely had any air...and my undergarments were soaked through.
To end my comments in this thread. I am not liking dry suit diving very much. However all of these experiences just drive me to work at it more and more. Originally the only reason I was interested in the dry suit specialty was because I wanted to start the rescue diver course right away after finishing my EFR, but I was told that I couldn't do that until spring unless I had a dry suit specialty. (and i didn't want to sit around for months with no diving experiences at all) Looking back, and considering the issues I had had with the dry suits,I do not want to do a rescue course in dry suits (although practice in those things with dry shell would only help to round out rescue training)
At this point, I finished the course and didn't die...so I guess that will earn me a certificate. With that said, I do believe I will arrange for instructor assisted non-curricular free dives to get in the ocean again with that dry suit to improve on my last finish. I don't want that certification until I feel confident that i can control myself in that suit.
AJ
Contributor
Had the same experience on my first drysuit dives. Did not like it at all and almost wanted to quit drysuit diving. After some 70 dives in drysuit I cannot image diving wet ever again Hang in there, it will get better every dive you do. You will also notice that you will be able to dive with less lead as you become more experienced Don't worry, this is a normal learning curve.
Hang in there, it will get better every dive you do. You will also notice that you will be able to dive with less lead as you become more experienced Don't worry, this is a normal learning curve.Cowtown44
Registered
This. Maybe the group can assist me in this process. New to DUI drysuit with SiTech valve under a Halcyon Eclipse 30 with HP 100. I'm using only enough air to take the extreme squeeze off. At depth, I'm feeling moderate pressure with a Santi 400 undergarment. Can you describe your venting procedure as you ascend?
My current problem is losing the slow ascent battle at 15-17 feet. I'm thinking I need to complete de-air the suit as a first step in ascents and, then, manage with the wing. I'd appreciate hearing people's ascend SOPs.
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