Diving with Side mounted cylinders ONLY

dafad-ddu · September 17th, 2006, 05:54 PM

Hello,

Has anyone dived with side mounted cylindes only for a number of years and then converted to DIR config?

Answers on the back of a postcard please...

M

Kevrumbo · September 18th, 2006, 06:28 AM

X-Scooter Video - info@dive-xtras.com

lizardland · September 18th, 2006, 11:10 AM

Quote: (Originally Posted by dafad-ddu)

Has anyone dived with side mounted cylindes only for a number of years and then converted to DIR config?

I've done a bit of sidemount diving over the years. When the "DIR" sidemount system got published on Techdiver I gave it a go. I didn't like it, I don't think it's either as comfortable or as streamlined as a traditional UK style sidemount system. I don't think it's as comfortable out of the water either than the UK system -- if you've got a bit of walking either before or after a sump then that is important.

I thought it was a bit of a bodge job. I had spoken to George Irvine by e-mail just a few weeks earlier about DIR sidemount, his reply was that he had never done any sidemount diving, had no interest in it and didn't really know anyone in his team who did. A few weeks later he published the system description -- I think it was for the sake of saying "we have a system" rather than developing a system that works.

My own view is that sidemount diving is beyond the scope of DIR. I cannot see how you can apply DIR principles in an environment that requires sidemount -- how can you assist a buddy or be assisted (or even keep an eye on him) when you can't see/reach him?

On the other hand, when I was diving in backmounts I always followed a DIR stylie config.

Joe Hesketh · September 18th, 2006, 12:38 PM

I don’t have much direct experience apart from once diving Dinas mine with Martyn Farr in his own kit.

As for DIR and side mount, we asked Danny about this during our Cave 1. Apparently, they’ve experimented with a number of side mount options and I seem to recall he settled on something similar to the set up described by GI3 in “that” e-mail, only the neck of the bottle, in addition to the regular clip, was held tight to the body with bungee looped round the neck of the tank and fastened to the backplate. However, unlike the UK system each reg was stowed back on the other bottle when not in use (which I can’t see being overly practical in a really tight passage…)

Other things some of their support team were doing was doing away with the backplate and sewing an inverted T of 2” webbing onto the back of an otherwise standard DIR harness (which again is getting more towards the UK style harness).

Danny did say that he hadn’t hit upon a rig that he was totally happy with, and that the system was not without compromise, both in terms of the issues Stuart mentioned[1] and also having sufficient gas reserves (in México, they often want to start exploring squirrelly cave, which only permits really small bottles, already several thousand feet back into an existing system). He mentioned one guy who was wearing a soft side mount harness underneath a regular back mounted doubles set up. When he got to the small passage, this guy would then ditch the doubles, clip them to the line, strap on his side mount bottles to the soft harness and crack on. Sounds like a bit of a nightmare though and god knows how you properly weight this dual rig?

Joe

[1] These issues still present themselves going through restrictions in standard DIR kit, albeit for more temporary periods, but that doesn’t mean that DIR precludes passing through restrictions. I think many of the full complement of “DIR things” don’t always apply in every environment (e.g. lights for signalling are useless on a 6m reef in bright sunlight, but again that doesn’t mean you can’t “dive DIR” in such conditions).

Kevrumbo · September 19th, 2006, 03:49 AM

An interesting snippet from SoCaltecDivers Forum from a Team taking a NSS-CDS Sidemount Course in Florida:

Quote:

OOA Situation, SM [Side Mount] divers.

Again,I think the best solution is to have the a SM diver with a 7 foot hose. In the event of an OOA situation the response would be just like the BM [i.e. "Back Mount"] way. If I am not breathing it, it is on my right shoulder d-ring. In the event of an OOA situation, 99.9% of the time I will see the other diver approaching and hand them the reg, just like on BM. I think this is important, especially in tight areas. Probably the worst case would be in a very tight area. In this case the 7 foot hose would be essential in getting the air to the other diver. The SM divers can switch tanks when they get to an open area if they choose.

Donating/switching tanks is a tough call. Swapping steel tanks takes careful thought. The divers can end up in an unbalanced situation which may cause more problems. Bracing against the ceiling will keep you from flipping over or flopping to one side, but then you have to handle a negatively buoyant tank. Settling on the bottom may make the actual swapping of the tank easier, but it may result in positive buoyancy and a silt nightmare. Still, it is probably the best method for swapping tanks. It is important that the two SM divers work together to swap tanks. Ideally, a clean rocky base would be the best place to switch. But why switch? If the SM divers are equipped with a 7 foot hose on the right tank, there is no need to switch, just perform the standard drill. The speed you gain in exiting independently would be more than offset by the time and energy it would take to switch.

I believe that in an OOA situation, a team that is not ‘sharing’ can exit much faster than a team doing the standard drill. Especially on scooters or through restrictions. This raises an important question. Is speed of exit more important than maintaining touch contact and reassurance with the OOA diver?

My philosophy is the exit determines the method. If you can comfortably exit using the standard OOA drill, do so. This method is tried and true and divers can perform it with their eyes closed (literally) and in their sleep.
The shortcomings of this method occur when the OOA situation occurs at max pen and it may take more gas to exit sharing air than it did to get to max pen or you have to pass one or more restrictions.

These are some examples:

A long exit without any help from the flow.

By exiting in touch contact you will be slower and the anxiety level will be higher possibly causing increased air consumption. Swapping tanks is probably a better choice for speed of exit, if you can swap tanks efficiently.

You need to pass a number of restrictions to exit. -

My favorite common example of this is Cow Springs. A lot of people back mount in there and I am not convinced that they consider the consequences of exiting on BM’s sharing air. You can certainly get a lot of help from the flow on the exit. But consider if the OOA event occurs past Not My Fault. That will be a challenge when passing through. Then you get to the lower restriction. Have any of you thought about how you would go through sharing air? I am confident I could grab almost any BM buddy pair, get them in the cave and tell them to exit the restrictions sharing air without planning it beforehand and most would fail. Videoing it would be interesting. Very few buddy teams would make it out, and even those would make a pretty interesting video.

In this scenario two SM divers on a long hose should choose to swap tanks before passing the restrictions as they would have difficulty sharing air through the restrictions.

For very tight passages where tanks have to be removed a standard configuration with two short hoses is probably still best as the extra long hose could come free from the tank. However, the next time you are diving with a mixed team of SM and BM divers or you are in a team of SM divers, ask if anyone has considered using a long hose.

caver95 · September 19th, 2006, 03:39 PM

Side mounting is something I know a little about, as far as out of air divers go, a diver has to have 2 failures. When side mount diving one must swap regs every few hundred PSI, BAR, keeping the tanks as close to the same pressure, this does 2 things keeps the diver from being way off balance, and if a failure of one tank does happen, the diver should have enough gas in the one tank to exit safely. The rule of thirds is ment for highflow cave. I dive with a long hose, for the backmounters in the team. I know a guy that dives with a 7ft on one bottle and a 5ft on the other, if he gets to a restriction that a tank needs to be pushed ahead or pulled behind or both. it does not matter which one is in front or behind, as the diver should never be out of reach of the other tank. I dont know about your DIR diving, I know long ago in the dark ages of cave diving everyone dived what was good for them, and everyone was different. Sidemount is the same way now, no one has come along with a system that will work for everyone, I guess most sidemounters just like to explore virgin cave that was past up by back mounters so untill some benevolent sidemount diver takes the time to work on something that will work for all right out of the box, we will not have DIR sidemount.

September 17th, 2006, 05:54 PM	#1 (permalink)
dafad-ddu(Offline) New Member Join Date: Apr 2006 Location: Liverpool Posts: 3	Diving with Side mounted cylinders ONLY Hello, Has anyone dived with side mounted cylindes only for a number of years and then converted to DIR config? Answers on the back of a postcard please... M

September 18th, 2006, 06:28 AM	#2 (permalink)
Kevrumbo(Offline) New Member Join Date: Dec 2005 Location: El Segundo CA, South Santa Monica Bay, USA Posts: 133	Scooter Diving with Side Mount Cylinder. . . X-Scooter Video - info@dive-xtras.com __________________ "Live never to be ashamed if anything you do or say is published [or posted] around the world --even if what is published is not true. . ."

September 18th, 2006, 11:10 AM	#3 (permalink)
lizardland(Offline) LCS Join Date: Nov 2005 Location: Evidently Chickentown Posts: 591	Quote: (Originally Posted by dafad-ddu) Has anyone dived with side mounted cylindes only for a number of years and then converted to DIR config? I've done a bit of sidemount diving over the years. When the "DIR" sidemount system got published on Techdiver I gave it a go. I didn't like it, I don't think it's either as comfortable or as streamlined as a traditional UK style sidemount system. I don't think it's as comfortable out of the water either than the UK system -- if you've got a bit of walking either before or after a sump then that is important. I thought it was a bit of a bodge job. I had spoken to George Irvine by e-mail just a few weeks earlier about DIR sidemount, his reply was that he had never done any sidemount diving, had no interest in it and didn't really know anyone in his team who did. A few weeks later he published the system description -- I think it was for the sake of saying "we have a system" rather than developing a system that works. My own view is that sidemount diving is beyond the scope of DIR. I cannot see how you can apply DIR principles in an environment that requires sidemount -- how can you assist a buddy or be assisted (or even keep an eye on him) when you can't see/reach him? On the other hand, when I was diving in backmounts I always followed a DIR stylie config. __________________ Can you imagine drifting along in the sea with your mouth open and a load of f***ing plankton going in? You'd like it, would you? www.westons-cider.co.uk The Lot isn't the only place to dive: http://www.lulu.com/content/613554

September 19th, 2006, 03:49 AM	#5 (permalink)
Kevrumbo(Offline) New Member Join Date: Dec 2005 Location: El Segundo CA, South Santa Monica Bay, USA Posts: 133	RE: Sidemount & OOG Scenarios. . . An interesting snippet from SoCaltecDivers Forum from a Team taking a NSS-CDS Sidemount Course in Florida: Quote: OOA Situation, SM [Side Mount] divers. Again,I think the best solution is to have the a SM diver with a 7 foot hose. In the event of an OOA situation the response would be just like the BM [i.e. "Back Mount"] way. If I am not breathing it, it is on my right shoulder d-ring. In the event of an OOA situation, 99.9% of the time I will see the other diver approaching and hand them the reg, just like on BM. I think this is important, especially in tight areas. Probably the worst case would be in a very tight area. In this case the 7 foot hose would be essential in getting the air to the other diver. The SM divers can switch tanks when they get to an open area if they choose. Donating/switching tanks is a tough call. Swapping steel tanks takes careful thought. The divers can end up in an unbalanced situation which may cause more problems. Bracing against the ceiling will keep you from flipping over or flopping to one side, but then you have to handle a negatively buoyant tank. Settling on the bottom may make the actual swapping of the tank easier, but it may result in positive buoyancy and a silt nightmare. Still, it is probably the best method for swapping tanks. It is important that the two SM divers work together to swap tanks. Ideally, a clean rocky base would be the best place to switch. But why switch? If the SM divers are equipped with a 7 foot hose on the right tank, there is no need to switch, just perform the standard drill. The speed you gain in exiting independently would be more than offset by the time and energy it would take to switch. I believe that in an OOA situation, a team that is not ‘sharing’ can exit much faster than a team doing the standard drill. Especially on scooters or through restrictions. This raises an important question. Is speed of exit more important than maintaining touch contact and reassurance with the OOA diver? My philosophy is the exit determines the method. If you can comfortably exit using the standard OOA drill, do so. This method is tried and true and divers can perform it with their eyes closed (literally) and in their sleep. The shortcomings of this method occur when the OOA situation occurs at max pen and it may take more gas to exit sharing air than it did to get to max pen or you have to pass one or more restrictions. These are some examples: A long exit without any help from the flow. By exiting in touch contact you will be slower and the anxiety level will be higher possibly causing increased air consumption. Swapping tanks is probably a better choice for speed of exit, if you can swap tanks efficiently. You need to pass a number of restrictions to exit. - My favorite common example of this is Cow Springs. A lot of people back mount in there and I am not convinced that they consider the consequences of exiting on BM’s sharing air. You can certainly get a lot of help from the flow on the exit. But consider if the OOA event occurs past Not My Fault. That will be a challenge when passing through. Then you get to the lower restriction. Have any of you thought about how you would go through sharing air? I am confident I could grab almost any BM buddy pair, get them in the cave and tell them to exit the restrictions sharing air without planning it beforehand and most would fail. Videoing it would be interesting. Very few buddy teams would make it out, and even those would make a pretty interesting video. In this scenario two SM divers on a long hose should choose to swap tanks before passing the restrictions as they would have difficulty sharing air through the restrictions. For very tight passages where tanks have to be removed a standard configuration with two short hoses is probably still best as the extra long hose could come free from the tank. However, the next time you are diving with a mixed team of SM and BM divers or you are in a team of SM divers, ask if anyone has considered using a long hose. __________________ "Live never to be ashamed if anything you do or say is published [or posted] around the world --even if what is published is not true. . ."

September 19th, 2006, 03:39 PM	#6 (permalink)
caver95(Offline) New Member Join Date: Dec 2005 Location: florida Posts: 23	Side mounting is something I know a little about, as far as out of air divers go, a diver has to have 2 failures. When side mount diving one must swap regs every few hundred PSI, BAR, keeping the tanks as close to the same pressure, this does 2 things keeps the diver from being way off balance, and if a failure of one tank does happen, the diver should have enough gas in the one tank to exit safely. The rule of thirds is ment for highflow cave. I dive with a long hose, for the backmounters in the team. I know a guy that dives with a 7ft on one bottle and a 5ft on the other, if he gets to a restriction that a tank needs to be pushed ahead or pulled behind or both. it does not matter which one is in front or behind, as the diver should never be out of reach of the other tank. I dont know about your DIR diving, I know long ago in the dark ages of cave diving everyone dived what was good for them, and everyone was different. Sidemount is the same way now, no one has come along with a system that will work for everyone, I guess most sidemounters just like to explore virgin cave that was past up by back mounters so untill some benevolent sidemount diver takes the time to work on something that will work for all right out of the box, we will not have DIR sidemount. __________________ anyone want to buy a knock off Gavin? send me an email.

September 18th, 2006, 12:38 PM	#4 (permalink)
Joe Hesketh (Online) New Member Join Date: Nov 2005 Location: London, UK Posts: 657	I don’t have much direct experience apart from once diving Dinas mine with Martyn Farr in his own kit. As for DIR and side mount, we asked Danny about this during our Cave 1. Apparently, they’ve experimented with a number of side mount options and I seem to recall he settled on something similar to the set up described by GI3 in “that” e-mail, only the neck of the bottle, in addition to the regular clip, was held tight to the body with bungee looped round the neck of the tank and fastened to the backplate. However, unlike the UK system each reg was stowed back on the other bottle when not in use (which I can’t see being overly practical in a really tight passage…) Other things some of their support team were doing was doing away with the backplate and sewing an inverted T of 2” webbing onto the back of an otherwise standard DIR harness (which again is getting more towards the UK style harness). Danny did say that he hadn’t hit upon a rig that he was totally happy with, and that the system was not without compromise, both in terms of the issues Stuart mentioned[1] and also having sufficient gas reserves (in México, they often want to start exploring squirrelly cave, which only permits really small bottles, already several thousand feet back into an existing system). He mentioned one guy who was wearing a soft side mount harness underneath a regular back mounted doubles set up. When he got to the small passage, this guy would then ditch the doubles, clip them to the line, strap on his side mount bottles to the soft harness and crack on. Sounds like a bit of a nightmare though and god knows how you properly weight this dual rig? Joe [1] These issues still present themselves going through restrictions in standard DIR kit, albeit for more temporary periods, but that doesn’t mean that DIR precludes passing through restrictions. I think many of the full complement of “DIR things” don’t always apply in every environment (e.g. lights for signalling are useless on a 6m reef in bright sunlight, but again that doesn’t mean you can’t “dive DIR” in such conditions).