Couple questions on a pony bottle for bail out

[John C. Ratliff]

Errol,

That is a beautiful video, and I appreciate your posting it. However, it is not my kind of diving.

When we (my wife and I) go to Rainier National Park, we prefer to hike/walk the trails. There are other ways of visiting the park, but to really see what is there we walk it.

In a similar manner, when I dive I prefer to swim. I have never ridden an underwater scooter, even though it looks like a lot of fun. Cost and availability are the main factors. I doubt my wife would want me to spring for the cost of the scooter, especially since I would use it only a few times a year. Perhaps that is the advantage of living in Florida rather than Oregon (though we have some areas that are pretty spectacular too). I have been working on different concepts of underwater swimming, which would be the equivalent of bicycling on land (I do a lot of bicycling too).

A couple of discussion points:

"A man in armor is his armor's slave." Robert Browning
This was the subheading of a chapter titled "Effect of Equipment on Diving Performance," by Glen H. Hgstrom, Ph.D., in the book, Human Performance and SCUBA Diving, Scripps Institution of Oceanography, LaJolla, California, April 10-11, 1970. While you are having a great time flying around the wreck, you are tethered to the scooter, and having to use it all the time. I'm not saying that's not a great dive, only very different from the type of diving I do.

I'm assuming that you were using Nitrox 32% for the dive, but no one had that marked on the cylinders.

Finally, with all that gear on, the need for a scooter to move around is obvious. Without the scooter, it is very difficult to swim efficiently through water with the drag of the gear.

Again, I'm not against this type of diving, only saying it is not my style.

SeaRat

 

[jadairiii]

I'm assuming that you were using Nitrox 32% for the dive, but no one had that marked on the cylinders.


SeaRat

Back gas was 21/35 trimix, with a 40 cuft of EAN 50 that we went to at 70'. The back gas were marked with labels and the 40's were marked with MOD labels.

 

[John C. Ratliff]

Errol,

Your video is much like the ones we witnessed from the Cousteau divers in his film, The Silent World. The underwater scooter rides there were equally breathtaking to yours.
[video=youtube;xCfwoNd2U6k]http://www.youtube.com/watch?v=xCfwoNd2U6k[/video]
I have never had the opportunity to dive in this manner. My current diving (pun intended) is under the rapids of the Clackamas River at High Rocks, which suits me well as I watch very small things happening which others disregard. Here is a log entry from my dive log for a recent dive, where I witnessed for over 20 minutes (holding onto the same rock) the red-sided shiner (Richardsonius baiteatus (Richardson)),spawning under the rapids in the Clackamas River:

I have watched this mating ritual in the North Umpqua River many times, but this is the first time I have observed for a long period of time these little fish mating in the Clackamas River. As I was watching, i was thinking that I should have a GoPro camera on my helmet to record some of these unique observations. It appears that the females are the larger of the two, and since these fish are identically marked, other than size it is difficult to tell males from females. I did not see any eggs broadcast, but did see the mass of fish (some 10-20 individuals) around one or two females and broadcasting sperm (white milk) into the water. The eggs, from observations in the past, are deposited into cracks between large, fist-sized rocks, and adhere to the bottom of these rocks. I did not disturb the rocks, and acted simply as an underwater naturalist observing without disturbing the rocks or fish. I had my SeawiscopeEY on, and so was able to see them very clearly at very close quarters (less than a foot from my face). My use of the double hose Healthways SCUBA hybrid regulator ensured that I wasn't disturbing these fish too. I noted a large-scale sucker fish come by, and try for eggs where the spawning had occurred, just as is the North Umpqua. I also saw a Northern Pike Minnow coming in, but it did not feed on anything (these fish are too big for this fish to eat, I think, as it was only about a foot long). I'll post a few photos I took years ago in the North Umpqua so you can tell what I was seeing (all these photos are Copyright John C. Ratliff).


Read more: Dives--2014 | Vintage Scuba Diving Community Forum

I am curious what camera/video system you used, as I am currently researching this? Also, how many were used to make this video?

Now, to get back to the op-ed, what were your emergency procedures in case of a failure of your primary breathing gas for this dive?

SeaRat

 

[Greg_Vic_Diver]

John, emergency procedures are all standardized for GUE and in this case would be to signal out of gas using the can light to get one of your buddies attention. This is the reason can lights are used on all dives...it's not really as much for light as it is used for signalling and keeping track of each other (although it is used for both). Gas would be shared via a 7ft long hose and each diver has enough reserve to cover a loss of gas for one other diver and have enough gas to get to the next gas switch which in this case would be at 70'. Each diver also has 1.5x the deco gas to cover a lost deco gas scenario (alternating deco gas/back gas ascent).

Also, one other point, when in proper trim and using the right fins this gear is not onerous in the water. I regularly swim without a scooter with double steel 130s for backgas and 2xAL80s and sometimes with an additional Al40. I have no problem moving around efficiently- this comes from a streamlined position in the water and efficient fin kicks (frog and modified frog kick).

 

[John C. Ratliff]

Greg_Vic_Diver,

Thank you for the explanation of emergency procedures standardized by GUE. Not all of us have been exposed to these, so this helps the discussion.

Now, as for the explanation of your "streamlined position," you really don't know what streamlining is about. As former Finswimming Director for the Underwater Society of America, I have to say a few things here. What you are describing is the antithesis of streamlining: "...when in proper trim and using the right fins this gear is not onerous in the water. I regularly swim without a scooter with double steel 130s for backgas and 2xAL80s and sometimes with an additional Al40. I have no problem moving around efficiently- this comes from a streamlined position in the water and efficient fin kicks (frog and modified frog kick)." There is no way you can be "streamlined" and "efficient" in the water while having four or five cylinders hanging off you. You would be swept away in the rapids I regularly swim under in that configuration. Here is just one of many examples of finswimming from the Philippine Finswimming Federation (see the link), which regularly competes finswimming. Note what is a streamlined position. Also, the frog kick is about the most inefficient kick possible in fins. The only way you are comfortable in the water using this configuration and kick is swimming very slowly. Here is efficient finswimming using scuba:
<span style="color: rgb(51, 51, 51); background-color: rgb(250, 250, 250);">[video=youtube;VeKRiwo2Zpo]https://www.youtube.com/watch?v=VeKRiwo2Zpo[/video]
[video=youtube;8Ty-7IBrCSo]https://www.youtube.com/watch?v=8Ty-7IBrCSo[/video]
Note that these competitors are not using a frog kick, and are using a monofin with the dolphin kick.

Now, a question concerning the op-ed on use of a pony bottle. You are not in the video dive above using the same gas in the pony bottle as in your main tanks (tri-mix). But one of the arguments made before is that these should be the same. Is there a contradiction here?

SeaRat

 

[Greg_Vic_Diver]

John,
I'll first address the question on the different gas. The Al40 in the video is actually a deco cylinder, used for accelerated decompression. It is not a pony bottle.

Now to your question on efficiency. It is more efficient to go slow when kicking underwater (note I didn't say quicker Drag forces increase exponentially with speed. Also, C02 build up is not good when diving. With those large single fins they would not be efficient moving a diver with heavy gear through the water ...nor would you have as much precise control of your position in the water. Also, they would kick up a massive amount of silt on the bottom.

With the frog kick and backkick I can be any where I want to be in the water column and move as efficiently as possible...even fully loaded with cylinders(and not kick up any silt on the bottom). I'd really recommend going to check out some GUE divers and examine them in the water if any are near you...once you see you'll understand. Using doubles on pretty much any dive is a non event.

Here is a video that may help:
http://m.youtube.com/watch?v=U5wliityRuU

 

[dumpsterDiver]

So let me get this straight "Dumpster Diver", I see you are an Instructor. Your rational is that planning a dive to include enough gas for 2 divers to make it safely to the surface is out of touch from how most people dive? As an instructor, are you incapable of planning that out and explaining it to students or your dive buddy? Don't you know how long your gas will last at any depth before you dive? Your justification is that poor training exists, training is becoming shorter and shorter and solo diving is a good option?
My strong suggestion is for divers to learn to dive more knowledgably and with more skill so that they enjoy are safer and have a lot more fun. It is really not that hard to learn to dive with greater skill, safety and efficiency. Your dive buddy is a choice, why not dive as a team? Anyone that is looking for information on how to improve their diving may want to check out a non profit organization called Global Underwater Explorers, diving is not rocket science. Invest in a Fundamental's course and I guarantee you will learn a lot and it will be worth every penny. I am not soliciting for students, just suggesting that those interested seek out better information. Some divers do amazing recreational and technical dives without need for a pony bottle, most do not. Decide which you wish to be and act accordingly.

Why does nitrox need to get dumped with partial pressure blending, never heard of a haskel or storing banked gas? Partial pressure blending should be almost gone by this point as much better alternatives exist and are in practice throughout the world.

Sorry. I was out diving with my pony bottle and couldn't respond. You seem to want to attack me and my knowledge rather than my recommendation to use air. Be careful, the moderators can come down on certain people if they even appear to be "getting personal". I have thick skin.

Apparently you want this thread to degrade into a GUE/DIR versus the world discussion. The OP is a simple recreational diver, the discussion gets very detailed into nitrox versus air. You want the discussion to become, "why you should never need a pony bottle".

Your basic premise is that super well trained teams of very attentive and coordinated divers and a particular type of gear make a pony bottle obsolete. I don't necessarily disagree with that, but what you fail to acknowledge is that the vast majority of people do NOT and will NOT dive like that. The coordinated team approach to diving just ain't happening for the majority of us, and many of us will decide to dive solo.

Also, some other people seem to think that divers are carrying a pony bottle primarily because they want "an out" after they run out of gas. A smart diver will NEVER run out of gas, but an unlucky diver may suffer a failure of his scuba unit which may necessitate the use of a redundant system.

The whole premise that pony bottles are only for weak, poorly trained divers who are so ill-trained (or so undisciplined) that they will not begin their ascent until it gets hard to breath is weak. .. it is very weak.. it actually is insulting and juvenile. It would be as silly as me saying that GUE divers are all weak and insecure and unable to dive independently.. and the proof of that is that they feel they must dive as a team .. to cover their inadequacies.. sounds stupid huh?

ps. I liked the video. Looks like fun - getting towed around by a machine on a sight seeing dive.

 

[John C. Ratliff]

John,
I'll first address the question on the different gas. The Al40 in the video is actually a deco cylinder, used for accelerated decompression. It is not a pony bottle.

Now to your question on efficiency. It is more efficient to go slow when kicking underwater (note I didn't say quicker Drag forces increase exponentially with speed. Also, C02 build up is not good when diving. With those large single fins they would not be efficient moving a diver with heavy gear through the water ...nor would you have as much precise control of your position in the water. Also, they would kick up a massive amount of silt on the bottom.

With the frog kick and backkick I can be any where I want to be in the water column and move as efficiently as possible...even fully loaded with cylinders(and not kick up any silt on the bottom). I'd really recommend going to check out some GUE divers and examine them in the water if any are near you...once you see you'll understand. Using doubles on pretty much any dive is a non event.

Here is a video that may help:
http://m.youtube.com/watch?v=U5wliityRuU

Greg,

I have watched your video, and I have looked at divers practicing techniques such as yours in the pool. Note in the photos that I am very familiar with wearing lots of equipment, and diving doubles. If you'll look at the photos of me in my double AL 72s in the 1980s in Clear Lake, you'll note that I am fairly well balanced and in control of buoyancy, without the use of your techniques. Believe it or not, the BC I'm wearing is the original back-mounted BC by Bill Herder, Deep Sea Bills in Newport, Oregon (Bill is now deceased), where he built the BC into the back of my wet suit (the white portion of my wet suit is the BC). It is more streamlined than the BCs I see in your videos, and provides the same basic function. At that time, Bill told me "I've become a 'push-button diver.'" That was what we called the type of diving your are doing at GUE in the 1970s when BCs were still being developed as a concept (and which I published on in NAUI News).

Concerning the divers practicing GUE/DIR techniques, we have a pool that is 18 feet deep (competition diving pool) and 50 meters by 25 yards wide. In the winter on Sundays they open it up to diving and kayaking. I have observed GUI divers, and they are obsessed with staying only about a foot off the bottom while "finning" along an a snail's pace. They rarely notice me in the water, and when I wave they don't acknowledge it at all. They are constantly looking at their gauges, and sometimes one another. I literally swim circles around them without building up an CO2 debt, and at my age that says something. These guys come across as arrogant and egotistical, to the point that they won't talk to or even acknowledge someone like me diving an antique double hose regulator, but swimming around them while they stare at their gauges.

I do have one regulator with a 7 foot long hose, but it is an original Calypso balanced-diaphragm regulator, with the original Calypso second stage as my primary on the long hose, and a second generation Calypso on a neck strap as my backup regulator. The gauge on it is an original submersible pressure gauge, with a round dial that dates back to the early 1970s, but still works fine. I have dived it several times, and it still works extremely well. I hope to dive it some day with someone set up as you describe.

Concerning fins and finning techniques, your techniques (frog kick and modified flutter kick) are great in confined environments where kicking up any silt is a life-threatening situation. But they are not really good for distance swimming underwater (ever done a timed 1500 yard or 2000 yard swim in doubles--I have in the U.S. Naval School for Underwater Swimmers). I have done a lot of study of finning, swim fin types over the year, and even developed my own scoop fins (see link). But they should be only one or two tools in a whole toolkit for swimming underwater. I would really like to see someone use the frog kick in the river currents I dive, and see how "efficient" they really are.

Now, about twin tanks--I have used them and continue to do so, but they are very, very heavy for the type of diving I do. On my dive Friday, I suited up at my car, walked down a steep pathway, crossed over river rocks, and down to the river's entry point. When I got out, I had to go up a rock face to a small trail, climb up about fifty feet of rock and dirt to get to the paved pathway back up (another 50-100 feet climb) to the roadway to walk back to my car. I do this with double 45s, my heaviest tanks, but it is quite a workout. To do so with anything heavier would be a bit much. Single tanks or my PJ tanks (which I used Friday) are much lighter, and much more enjoyable at my age.

Back on point, a single tank with a pony bottle would do just fine for my type of diving; I however use a single tank with a J-valve up, and that becomes my reserve.


SeaRat

 

[rivers]

I've been debating whether or not to weigh on this thread and have decided to. First off, I am a fan of GUE as an agency and have chosen to take a majority of my more advanced training with GUE. As my diving advanced (slightly deeper, light deco all in a max of 35m), moving to a twinset made sense, as did adding a stage (currently have a fundies rec pass, with rec 3 in 2 weeks time). Saying that, I have many a diving friend who are quite happy doing simple recreational dives in the 0-30ish metre range in "standard recreational kit" (standard jacket and reg set-up and yeah, sometimes a pony). These are divers who don't have any deco in their future, most of their dives are a max of 25m, with the occasional dive hitting 30m. They don't need twinsets. They aren't doing dives that require them. They don't want to buy an entire new set of kit to go with it. So they opt for a pony for redundancy. They practice deploying it, passing it off, etc so that way if they need to use it, they can. Sometimes, sh*t happens. You can be the best buddy pair/team in the world and you may get separated (vis isn't the greatest in the UK. I've been on a dive where a GUE team lost one member, later found, due to the vis. it happens). They plan the dive for the gas they have available, follow minimum gas rules, etc. Sure, if they're stressed or have to work a bit on a deeper dive, the bottom time is shortened. But that's diving. The stick to the plan. So what, our configurations are different, we have a great time diving together. And they are divers that I trust could help me if needed.
The only thing that matters when it comes to kit is it's appropriate for the dive you are planning, you have enough gas to do the dive planned, and you are competent in your kit configuration (if you dive a pony, you are practiced in switching to it and handing it off, if you dive twins, you can reach your valves, etc).

 

[DaleC]

A very good post rivers.