GUE gear config

[Ayisha]

...To the best of my limited knowledge, GUE doesn't have procedures (yet at least) for diving in rivers, or high currents, etc, because it's not the target environment of the agency for conservation or exploration. On the other hand they have procedures (I assume) for cave diving against currents, which objectively have no trouble executing safely using jetfins, or other equivalent fins.

There are GUE instructors teaching in rivers and high flow caves, and their students are trained in the procedures. Bob Sherwood, Heison Chak, and Michael Pinault, GUE instructors, all regularly teach GUE courses in the St Lawrence river. Other GUE instructors visit and teach courses or workshops. That is where my Fundies course was. Like any dive course in challenging conditions (cold, current, low viz, etc.) should be, the course information is tailored to the environment.

Even in a workshop in May, they taught "River Diving Techniques", as can be seen in this screenshot of the schedule:

 

[ginti]

You got the point...
Efficiency is defined as the ratio between the distance traveled (in meters) and the energy spent (in Joules), as a function of speed.
For a given diver, using a given set of fins and kicking style, efficiency usually shows a bell-shaped curve, peaking at an "optimal" speed.
Short and rigid fins (such as the Scubapro version of the Jetfin, in which the original Venturi boost has been almost entirely removed), with frog-style kicking, usually have a good efficiency at slow speed.
Flexible, longer fins (such as the original Beuchat Jetfins or the Mares Avanti 4) and flutter kicking provide higher efficiency and higher optimal speed.
Competition-style monofins have low efficiency, but their optimal speed is very large.
Deep free divers use very long and very flexible carbon fiber fins or monofins, employing dolphin-style kicking, which provide the ultimate efficiency at medium speed.
Different fins and different kicking styles for different tasks....
But it must be understood that in the efficiency-speed curve there is a third factor, which is the human factor: geometry of legs and articulations, muscular strength, capability of sustaining a prolonged effort, capability of controlling motion, attitude and hydrodynamic asset, etc.
In a finned swimming course the instructor and the student performs a number of tests, with the goal of finding the optimal fins for the subject, and the optimal kicking pattern.
It takes MONTHS, in some cases YEARS to refine a finned swimmer. During this long period the muscles grow stronger, the motion control improves, and hence the diver needs to change fins two or three times (generally going towards longer and/or stiffer fins, providing more energy transfer).
My experience as a finned swimming instructor was entirely club-based and not-profit.
I followed some students for many years, seeing their slow but continuous improvement.
This is entirely unfeasible in the world of professional instructors and for-profit teaching agencies.
After doing this for 5 years I stepped to become a "pro", working in holidays resorts.
I had to change from 6-months courses to 6-days courses.
Here I appreciated the benefit of standardisation over personalisation. Using standard equipment is just one ingredient: what matters is to create a standardised diving system, with standard procedures, standard skills, standard planning, standard thinking!
This is both safer and easier.
A standardised diver can be stupid, and still be safe!
But having seen before the much higher efficiency, speed and performance obtainable with not-standard tools and methods, I feel to be correct to explain which are the limits inherent in adopting a standardised approach.
Among the various standardised methods, GUE emerges as one requiring very strict compliance, providing specialised and optimised approach to a set of very specific requirements for tech diving as a member of a team in caves, wrecks, etc..
But these methods and standards cannot be optimal ALWAYS. In some environments or for some specific tasks the optimal solution is different.
In my opinion a good diver should possess both the discipline and knowledge for complying with the standardised diving approach, but also the freedom and fantasy required for developing "heretic" methods to be used in out-of-standard situations.
In some cases I was the DM who had to solve issues with customers who were rigid in their compliance to standards, not realising that they were in a completely different new environment, which required a different approach.
So I repeat my suggestion to the OP: it is very good to be trained within an highly standardised "system" such as GUE. But one should keep control of his choices, adapting them to the actual needs, which in some selected cases can require to behave differently from the standard.

While I agree that standardized isn't optimal (by definition), I doubt that one cannot properly use jetfins or similar in the Maldives, because many divers use the jetfins in high current/flow (see @Ayisha 's post #101). The guys you mentioned who were frog kicking in high current were simply newbies with their equipment or poorly trained, as frog kick isn't suitable for high current/flow.

That said, I will be in the Maldives next year for the first time, at that point I will know

I've experienced one before. We were towards the end of the dive, can't remember exactly but probably around 10-15m. We were on a liveaboard in Galapagos so diving in a group of 7 with no designated buddy pairs (my husband who is my normal buddy opted to skip this dive) and a guide. Zero visibility dive, super cold, we lost some of the group, so two of us decided to call the dive and indicated to the guide we were going to go up together. Halfway up my ad hoc buddy came to me with out of air signal and grabbed my SS1 before I can give him my primary. I indicated we should swap and we did, then locked arms and ascended normally, did our safety stop normally, and surfaced normally. There was a shoulder dump valve on my old bc which worked fine. It was not comfortable - I have a dive alert attached to my SS1 so the whole thing is quite stiff, and we were bumping into each other a bit, but I don't recall having safety issues. The OOA buddy was a dive instructor w >3000 dives (who still breathed his air dry...) so perhaps a less experienced one would present more issues. But then again someone super inexperienced / panicked would likely not be familiar with GUE either, if they tried to grab the octopus on the necklace wouldn't that be worse? Honest question - I am a casual vacation diver, mostly go on liveaboards, and have seen only 3 GUE divers in all of my trips so far. My SS1 with the new BC is not very comfortable due to differences in inflator hose lengths so I am rethinking it.

(1) in your OOA experience you were lucky because you were already so surfacing. But what if you had to swim a lot?
(2) a panicked diver wouldn't even see the secondary regulator on the necklace, because it is under the chin and it is basically hidden. On the other hand, the regulator you are breathing is super easy to spot, it is the first one they will see almost always and the one they will grab if they're panicking. EDIT: the only situation they might see the necklace regulator is if they are below you. Still, they will probably see first the one you are breathing from

 

[Angelo Farina]

While I agree that standardized isn't optimal (by definition), I doubt that one cannot properly use jetfins or similar in the Maldives, because many divers use the jetfins in high current/flow (see @Ayisha 's post #101). The guys you mentioned who were frog kicking in high current were simply newbies with their equipment or poorly trained, as frog kick isn't suitable for high current/flow.

That said, I will be in the Maldives next year for the first time, at that point I will know

(1) in your OOA experience you were lucky because you were already so surfacing. But what if you had to swim a lot?
(2) a panicked diver wouldn't even see the secondary regulator on the necklace, because it is under the chin and it is basically hidden. On the other hand, the regulator you are breathing is super easy to spot, it is the first one they will see almost always and the one they will grab if they're panicking. EDIT: the only situation they might see the necklace regulator is if they are below you. Still, they will probably see first the one you are breathing from

Original Jetfins by Beuchat? Sure, they are great in high current scenarios.
I owned them!
Their Venturi channels are optimised for fast flutter kick with straight legs. Really great for short burst at high speed.
The problem is with the crap Jetfins produced under license by Scubapro.
Almost no flexibility and the Venturi channels are made flat.
The result is that with the Scubapro Jetfins the most efficient propulsion became frog kicking, a method which does not rely on the elastic response and flexibility of the fins, and which produces propulsion only during half of the cycle.
This created a vicious circle: with SP Jetfin, flutter kick is tiring and inefficient, so divers tend to use frog kicking everywhere, even when absolutely wrong.
On the other side, people being trained to cave diving, where frog kicking is required, are suggested to use SP Jetfins, as "they are the best for frog kicking".
All this appears absurd to me. The original Beuchat Jetfin were excellent for flutter kick and decent for frog kick (not much worst than the SP ones).
After accepting the concept that one should use equipment AND kicking style suitable to the environment, it is clear that you cannot frog kick for winning the current in channels at Maldives.
So you can well use your Beuchat Jetfins if you learned properly how to flutter kick with them (the presence of Venturi channels requires a different flutter kick than normal flat fins).
If instead you insist to frog kick with paddle fins, I suggest that you avoid diving in Maldives channels or other not-drifting high current scenarios.

 

[mariosx]

You got the point...
Efficiency is defined as the ratio between the distance traveled (in meters) and the energy spent (in Joules), as a function of speed.

I think then that I have an important extra note. Efficiency in scuba should also have the additional constraint on maximizing duration, thus minimizing speed to some threshold (don't forget that this is a recreational activity for most of us).

I have never heard anybody saying "Let's go for a 200m dive (meaning horizontal distance covered)", but I have heard many saying "Let's go for an 1 hour dive". And unless during a rescue situation, I bet most people (if not all) don't want to brake records on distance traveled by tank.

For a given diver, using a given set of fins and kicking style, efficiency usually shows a bell-shaped curve, peaking at an "optimal" speed.
Short and rigid fins (such as the Scubapro version of the Jetfin, in which the original Venturi boost has been almost entirely removed), with frog-style kicking, usually have a good efficiency at slow speed.

Which makes them ideal for 99% of divers, rec or tec diving for recreational purposes.

Flexible, longer fins (such as the original Beuchat Jetfins or the Mares Avanti 4) and flutter kicking provide higher efficiency and higher optimal speed.
Competition-style monofins have low efficiency, but their optimal speed is very large.
Deep free divers use very long and very flexible carbon fiber fins or monofins, employing dolphin-style kicking, which provide the ultimate efficiency at medium speed.
Different fins and different kicking styles for different tasks....
But it must be understood that in the efficiency-speed curve there is a third factor, which is the human factor: geometry of legs and articulations, muscular strength, capability of sustaining a prolonged effort, capability of controlling motion, attitude and hydrodynamic asset, etc.
In a finned swimming course the instructor and the student performs a number of tests, with the goal of finding the optimal fins for the subject, and the optimal kicking pattern.
It takes MONTHS, in some cases YEARS to refine a finned swimmer. During this long period the muscles grow stronger, the motion control improves, and hence the diver needs to change fins two or three times (generally going towards longer and/or stiffer fins, providing more energy transfer).

Great info, that also aligns with my experience as a fairly good competitive swimmer back in the day. We were not using fins competitively at least, but there is a lot of overlap on what you describe, and different athletes had to perform slightly different motions due to different anatomy.

Here I appreciated the benefit of standardisation over personalisation. Using standard equipment is just one ingredient: what matters is to create a standardised diving system, with standard procedures, standard skills, standard planning, standard thinking!
This is both safer and easier.
A standardised diver can be stupid, and still be safe!
But having seen before the much higher efficiency, speed and performance obtainable with not-standard tools and methods, I feel to be correct to explain which are the limits inherent in adopting a standardised approach.
Among the various standardised methods, GUE emerges as one requiring very strict compliance, providing specialised and optimised approach to a set of very specific requirements for tech diving as a member of a team in caves, wrecks, etc..
But these methods and standards cannot be optimal ALWAYS. In some environments or for some specific tasks the optimal solution is different.

Also for different people the optimal solution is different, just considering the preference for comfort, etc. And when using an optimization process, especially in multi-objective optimization problems such as scuba, it's practically impossible to provide an optimal setup for every situation and diver. Also, computing the exact optimal solution, even in theory, can be an extremely difficult problem, and most/all people settle for a near-optimal solution within some confidence proximity to the true optimal. My argument and the argument of most GUE divers/instructors/etc is that GUE configuration has iin the vast majority of the scenarios an accceptably short proximity to the optimal solution (often other configuration might fall in the same area).

In my opinion a good diver should possess both the discipline and knowledge for complying with the standardised diving approach, but also the freedom and fantasy required for developing "heretic" methods to be used in out-of-standard situations.

By definition out-of-standard situations are free playground, right? You just need one box to not be ticked to not fullfill the requirements of a GUE dive. And the class of divers in GUE that face such situtations daily (for example divers from WKPP) indeed discover the standards of the future with the process you described. Probabilistically speaking though if a GUE diver ends up in such situation, then they did something wrong in the process. If they are just unlucky, at least during my GUE-F class, I was reminded often that the goal is not to produce a GUE robot, but a thinking diver. Something that is being promoted a lot during the class to my experience.

 

[mariosx]

There are GUE instructors teaching in rivers and high flow caves, and their students are trained in the procedures. Bob Sherwood, Heison Chak, and Michael Pinault, GUE instructors, all regularly teach GUE courses in the St Lawrence river. Other GUE instructors visit and teach courses or workshops. That is where my Fundies course was. Like any dive course in challenging conditions (cold, current, low viz, etc.) should be, the course information is tailored to the environment.

Even in a workshop in May, they taught "River Diving Techniques", as can be seen in this screenshot of the schedule:
View attachment 735212

Awesome. Good to know.

 

[Imla]

Continuing to read this thread I keep getting surprised by the incessant focus on SPEED. The OP clearly voiced a wish to learn precision propulsion techniques. While freediver finning techniques are superb when doing freedives, these techniques often influence the environment in a degree that accomplishing your objective (ie photography) soon becomes impossible.
Personally if find NOTHING more annoying than having to swim after speedy gonzales when it isnt necessary. Comparing a diver properly geared for a fun dive, whether it is OW or Overhead VS a freediver doing a dynamic swim is not even comparing apples and oranges, we are comparing the kitchen sink to mount everest.
Oh... and diving the Maldives with JetFins and doing macro photography is absolutely possible with the kicks you can learn in GUE classes.

 

[ginti]

Original Jetfins by Beuchat? Sure, they are great in high current scenarios.
I owned them!
Their Venturi channels are optimised for fast flutter kick with straight legs. Really great for short burst at high speed.
The problem is with the crap Jetfins produced under license by Scubapro.
Almost no flexibility and the Venturi channels are made flat.
The result is that with the Scubapro Jetfins the most efficient propulsion became frog kicking, a method which does not rely on the elastic response and flexibility of the fins, and which produces propulsion only during half of the cycle.
This created a vicious circle: with SP Jetfin, flutter kick is tiring and inefficient, so divers tend to use frog kicking everywhere, even when absolutely wrong.
On the other side, people being trained to cave diving, where frog kicking is required, are suggested to use SP Jetfins, as "they are the best for frog kicking".
All this appears absurd to me. The original Beuchat Jetfin were excellent for flutter kick and decent for frog kick (not much worst than the SP ones).
After accepting the concept that one should use equipment AND kicking style suitable to the environment, it is clear that you cannot frog kick for winning the current in channels at Maldives.
So you can well use your Beuchat Jetfins if you learned properly how to flutter kick with them (the presence of Venturi channels requires a different flutter kick than normal flat fins).
If instead you insist to frog kick with paddle fins, I suggest that you avoid diving in Maldives channels or other not-drifting high current scenarios.

I probably wasn't clear.

Frog kicks in high current are wrong, period. We both agree on this point because it's simple physics - there isn't much to argue. And any GUE instructor in this world agree with that.

My curiosity is whether SP jetfins are really as crap as you say for the Maldives. The reason why I am so curious is that many people use SP jetfins in high current with pretty decent outcomes (again, see post #101)

I don't know myself if you're right or not. I trust you, but I also trust the others. Therefore, next year I will try other fins just to make the comparison, and then I will know.

But that has nothing to do with frog kicking, which I would never use in high current.

Also, let me add two things:
1) always frog kicking is AGAINST any principle of GUE. The principle of GUE is use the right kick for the situation.
2) standardisation doesn't mean to use standard equipment in a situation where they are wrong. If a piece of equipment is wrong in a specific situation, the diver needs to adapt. The point here is how to define wrong, but this is another subject.

I can see that you are quite loud against GUE. I don't know why, since in your own words you don't have much experience about it. But it's a pity, because you have a great culture about physics and about scuba diving, and a more open approach could lead to a more constructive dialogue or maybe, it's just me misinterpreting what you write, which is definitely possible since communication on internet is what it is... If this is the case, pleas forget this last paragraph

 

[Angelo Farina]

I probably wasn't clear.

Frog kicks in high current are wrong, period. We both agree on this point because it's simple physics - there isn't much to argue. And any GUE instructor in this world agree with that.

My curiosity is whether SP jetfins are really as crap as you say for the Maldives. The reason why I am so curious is that many people use SP jetfins in high current with pretty decent outcomes (again, see post #101)

I don't know myself if you're right or not. I trust you, but I also trust the others. Therefore, next year I will try other fins just to make the comparison, and then I will know.

But that has nothing to do with frog kicking, which I would never use in high current.

Also, let me add two things:
1) always frog kicking is AGAINST any principle of GUE. The principle of GUE is use the right kick for the situation.
2) standardisation doesn't mean to use standard equipment in a situation where they are wrong. If a piece of equipment is wrong in a specific situation, the diver needs to adapt. The point here is how to define wrong, but this is another subject.

I can see that you are quite loud against GUE. I don't know why, since in your own words you don't have much experience about it. But it's a pity, because you have a great culture about physics and about scuba diving, and a more open approach could lead to a more constructive dialogue or maybe, it's just me misinterpreting what you write, which is definitely possible since communication on internet is what it is... If this is the case, pleas forget this last paragraph

I have absolutely nothing against GUE, which by far is the best integrated standardised diving system, including training.
Whenever one needs to employ a team approach to cave/wreck/deco diving, GUE is just perfect.
The problem comes from SOME divers, who, after being primed with the GUE standardised approach, do not accept that for some other tasks other approaches can be better. Gue for them becomes a religion...
This problem affects a small, but vocal, percentage of GUE-trained divers (not instructors, in my experience) who think that the standardised approach they did learn is the only "right" one.
These people are the cause of criticism, not the GUE method itself.
I see that you are not among these guys, as most correctly trained GUE divers are. The problem I had as a divemaster at Maldives was with just 3 or 4 self-proclaimed technical divers, who did not accept to adapt to the strict standardised not-GUE procedures which were developed and employed in our touristic organization (Club Vacanze).
They were vocal about the fact that there is just one "right" way, their one!

Back to Jetfins. It is a long story, I will make a specific post later with photos.
What you need to know is that in over 50 years they had at least 5 generations. They changed material, type of foot pocket, number and geometry of the Venturi channels and blade length.
Both Beuchat and Scubapro manufactured them, not counting copies from a dozen of other manufacturers. Scubapro did employ at least 3 factories (Italy, Usa and somewhere in far east).
All the original Beuchat and one generation of Scubapro were long and elastic, well suited for fast and efficient kicking.
But for cave diving, mostly the short, rigid, paddle-type version is used.
If you have these ones, performing efficient and fast flutter kicking is very hard. They are more efficient for frog kicking.
So, if you do not own the long, flexible Jetfins, I recommend changing your short, rigid ones before a trip to Maldives....

 

[ginti]

I have absolutely nothing against GUE, which by far is the best integrated standardised diving system, including training.
Whenever one needs to employ a team approach to cave/wreck/deco diving, GUE is just perfect.
The problem comes from SOME divers, who, after being primed with the GUE standardised approach, do not accept that for some other tasks other approaches can be better. Gue for them becomes a religion...
This problem affects a small, but vocal, percentage of GUE-trained divers (not instructors, in my experience) who think that the standardised approach they did learn is the only "right" one.
These people are the cause of criticism, not the GUE method itself.
I see that you are not among these guys, as most correctly trained GUE divers are. The problem I had as a divemaster at Maldives was with just 3 or 4 self-proclaimed technical divers, who did not accept to adapt to the strict standardised not-GUE procedures which were developed and employed in our touristic organization (Club Vacanze).
They were vocal about the fact that there is just one "right" way, their one!

Ok, got it. I actually agree with you, and there are stories here on the forum. I remember one about a guy who just after a GUE fundamental (I don't remember if it was the full course or just the first part) wanted to teach the right way to two divers who were tech1 and tech2 certified...

Back to Jetfins. It is a long story, I will make a specific post later with photos.
What you need to know is that in over 50 years they had at least 5 generations. They changed material, type of foot pocket, number and geometry of the Venturi channels and blade length.
Both Beuchat and Scubapro manufactured them, not counting copies from a dozen of other manufacturers. Scubapro did employ at least 3 factories (Italy, Usa and somewhere in far east).
All the original Beuchat and one generation of Scubapro were long and elastic, well suited for fast and efficient kicking.
But for cave diving, mostly the short, rigid, paddle-type version is used.
If you have these ones, performing efficient and fast flutter kicking is very hard. They are more efficient for frog kicking.
So, if you do not own the long, flexible Jetfins, I recommend changing your short, rigid ones before a trip to Maldives....

I am not sure if I will buy a pair of fins just for one trip. I will try to rent if possible... But I will see next year.

 

[mariosx]

I see that you are not among these guys, as most correctly trained GUE divers are. The problem I had as a divemaster at Maldives was with just 3 or 4 self-proclaimed technical divers, who did not accept to adapt to the strict standardised not-GUE procedures which were developed and employed in our touristic organization (Club Vacanze).
They were vocal about the fact that there is just one "right" way, their one!

These divers that needed to be rescued for sure were not following GUE protocols: (Rule 1: Always be a thinking diver), and although I have never meet such obnoxious GUE diver myself for sure they exist and they do not bring any positive effect to the themselves and the community.

Saying that, it seems to be a vicious cycle. To become devil's advocate, especially if somebody is working in a touristy scuba resort, it might become hard to distinguish genuine valid and useful information/advise and comments due to pure incompetence, spite, etc. Again, I am not defending them and personally in such cases I discuss it with the DM to understand the reasoning. If I agree or not care enough, I just follow the advice at least for this dive, or else I refuse to dive without mentioning the source of my training. So:

• Last week during my PADI drysuit class, I took the knee after having 2 minutes the instructor explaining to me what he meant. It couldn't register to my brain since I was hovering comfortably motionless in a fixed position, and last time I did it was only the first 5 minutes of my OW class to determine weighting. After I asked him if it was necessary, he said that it's better to be more stable and conserve energy.
  • Total nonsense, and it was actually more difficult for me where I had to balance vertically with my wing while my legs where in contact with the ground.
• More than 2 times in the past I had instructors at touristy dive centers initially not allowing me to dive with my long hose, because "this is only for penetration/extremely technical divers, and you will strangle yourself".
  • Total nonsense of course. Most such arguments/comments stop when I ask them to try to strangle me with it, or when I ask them to practice S-drill with control ascent and shooting DSMB in parallel (something that with my LH setup it's trivial). I seriously considered calling off the dive in one case, until the DM stopped pushing it.
• Once a DM insisted with more than 2 comments on dropping my jetfins and go for some split fins because they are heavy and I was diving wetsuit.
  • Also nonsense because I have at least 30 dives with my jetfins in wetsuit and I had no issue with my trim. I asked him if I could hover and move backwards with his splitfins, and he answered ofc. I kept my fins and enjoyed my dive. Thankfully I had my camera that day and have a 40 second clip of him trying to hover and move backward, which involved fining with his hands, pushing rocks and finally turning 180 and hitting a student with his fins.
• Many other ridiculous comments/advises/etc that I had just refuse or accepted with the knowledge that I am doing something worse just not to ruin the experience for my friends or other divers.

With the many people I have interacted within GUE I have never heard such ridiculous claims, misinformation, and just pure incompetence. Again, without defending the divers you mentioned, I try to give the opportunity to many recreational scuba professionals explain me their position and have a discussion, but these experience, and often their self-assumed "authority" requires a ton of effort. And not only because every new advice has to compete with all the other wrong comments... The majority of the DMs I have dive with couldn't hover although they truly try to many times during the dive. And if somebody as myself, a mediocre diver, during my OW with less than 40 dives could display better skills in the water (on any aspect) that learned in less than 3 dives of proper instruction, than the self-proclaimed 4 digit "experienced" DM or Instructor of X agency, then trust towards such professionals becomes very very hard. So statistically, not many professionals have your background, and unfortunately the easiest (but suboptimal) strategy, probabilistically speaking, is simply to ignore thus I have started avoiding diving with not GUE-friendly LDSs.

Something that truly makes a difference on getting a new advice or not from non-GUE professionals, is competence and their tone. So, good professionals like yourself, that know that at least a large portion of other professionals (to my experience) are not as competent as they should, I think they could benefit a bit on their interactions with such divers by getting some understanding on their experience with other professionals, maximizing outcomes for both parties. Of course I am not saying that you lack this understanding or skills, my comment is attempted to be more general and potentially benefit other good non-GUE professionals, that definitely exist.