Floridian influence on rebreather design and configuration

[JonG1]

Following on, and prompted by the GUE thread recently and a few others, I thought it would be interesting to understand a bit more about the history and considerations that have gone into rebreather configuration and design from the influences of the WKPP, GUE, KUR and others who have been at the forefront of cave exploration at significant depth and distance for decades.

For instance what prompted the addition of the JJ D7 configuration alongside the RB80, why did KUR choose the Fathom, why solenoid for GUE and Mccr for KUR (I realise there are some generalisations here but you get the gist).

When GUE were considering an alternate option what other units did they test, how did they evaluate them, what was the criteria they were assessing them against, why did others fall short?

Why does a diver choose the RB80 over the JJ or Fathom?

Why do KUR go SM for bailout and GUE stage and leash?

It may be we can spin this further in a (good natured way) towards the differences in RB configuration generally and what has influenced decisions to deploy them in the myriad options out there.

The following links may prove useful as back ground resources:

The Thought Process Behind GUE’s CCR Configuration

Global Underwater Explorers is known for taking its own holistic approach to gear configuration. Here GUE board member and Instructor Trainer Richard Lundgren explains the reasoning behind its unique closed-circuit rebreather configuration. It’s all about the gas!

gue.com

The RB80 Semi-closed Rebreather: A Successful Exploration Tool

What rebreather has arguably logged the most exploration kilometers since its market introduction in 1998—an estimated 160 km plus (100 miles plus for you Imperialists)—and continues to rack up the klicks? It’s Halcyon’s RB80 passive-addition, semi-closed rebreather. Here WKPP greybeard and RB80...

gue.com

Halcyon Dive Systems

Halcyon began as a group of divers who knew exactly what they wanted, but could not find it in any dive store. Our passion for diving led us to designing wings and lights to satisfy ourselves.

halcyon.net

FATHOM Mk III CCR - Fathom Dive Systems

www.fathomdive.com

 

[kensuf]

Many KUR members first foray into CCR diving was the venerable KISS Classic, which is an mCCR. Guys like Hemphill were pushing the limits of the KISS (including making custom scrubbers) back in the early aughts, but that drove a lot of the philosophies that went into the Fathom. The Fathom was designed by two KUR board members (Pitkin and Roberson) with input from several other KUR divers (McCoy, Hemphill, etc). The design considerations were focused on simplicity, ability to grow as a platform, and capability. Sidemount bailout / DIL was chosen for a couple of reasons, 1. most of the guys were already very accomplished OC SM divers, so it was already a natural and comfortable configuration, 2. some CCR platforms don't lend themselves well to using BM bailout, 3. the logistics of exploration within Twin Dees/Weeki make BM bailout impossible - the entrancy is tiny, you can't get a BM CCR w/Bailout into the entrance, as it is most people go in basically stripped and then don their bailout once we hit "the fitting room" at 40'.

In terms of the GUE JJ configuration, I can't really speak to that, but I'm pretty sure that although GUE HQ is in Florida, most of the configuration driving the GUE JJ was figured out by Europeans working on a few projects where a CCR made logistical sense (i.e. Mars). So saying that the GUE JJ is "Florida influenced" may be correct in terms of where the GUE HQ is, but saying "Florida designed" may be incorrect.

The RB80 was designed in Europe, I'm pretty sure it was originally designed for cave exploration in France. While it is heavily used by the WKPP for it's simplicity and robustness, again I'm not sure it could be called a "Florida" thing. Stages and a leash are an obvious extension to the OC diving the WKPP used to do. The first rebreather that the WKPP used was the PVR-BASC, designed by Jack Kellon, aka The Fridge. That was "Florida designed" and about the size of your typical Yugo.

 

[Doby45]

about the size of your typical Yugo.

Not the "deluxe Yugo" model?

 

[Jack Hammer]

In terms of the GUE JJ configuration, I can't really speak to that, but I'm pretty sure that although GUE HQ is in Florida, most of the configuration driving the GUE JJ was figured out by Europeans working on a few projects where a CCR made logistical sense (i.e. Mars). So saying that the GUE JJ is "Florida influenced" may be correct in terms of where the GUE HQ is, but saying "Florida designed" may be incorrect.

Yep, the guys diving the Mars in Sweden were using that unit and configuration. Other units were considered and pushed for but due to the JJ already being heavily used in several areas with success and the influence of those folks that configuration was adopted.

 

[JonG1]

Thanks kensuf, out of interest what were the drivers for moving away from the KISS, duration and flood recovery presumably?

If KUR had SM experience was that due to the type of caves they were surveying or a choice based on streamlining of kit?

Why had GUE deep wreck projects like Mars moved towards closed circuit over the rb80?

Maybe gas logistics because the 80 is an extender?

 

[Degenerate]

Thanks kensuf, out of interest what were the drivers for moving away from the KISS, duration and flood recovery presumably?

If KUR had SM experience was that due to the type of caves they were surveying or a choice based on streamlining of kit?

Why had GUE deep wreck projects like Mars moved towards closed circuit over the rb80?

Maybe gas logistics because the 80 is an extender?

I recall reading something about the bubbles from OC/RB80 could cause damages to the wood of Mars, and therefore using CCR was a better option.
Probably not the only reason though.

 

[kensuf]

Thanks kensuf, out of interest what were the drivers for moving away from the KISS, duration and flood recovery presumably?

If KUR had SM experience was that due to the type of caves they were surveying or a choice based on streamlining of kit?

Why had GUE deep wreck projects like Mars moved towards closed circuit over the rb80?

Maybe gas logistics because the 80 is an extender?

The KISS Classic was a good unit for the 1990s, but had zero flood recovery and a few quirks. While a few people had custom scrubbers milled for it, the Fathom is a large evolution.

Regarding SM, everything had to do with exploration and these guys were doing that for years before it became a popular configuration, heck Brett Hemphill and Curt Bowen effectively designed one of the earliest commercial SM kits (the Armadillo). The first time I met Brett was when he asked the NACD for support for the Crystal Beach project back in 1995, which is a cave with a no-mount entrance.

I can't answer the GUE JJ vs RB80 questions, sorry.

 

[jadairiii]

I recall reading something about the bubbles from OC/RB80 could cause damages to the wood of Mars, and therefore using CCR was a better option.
Probably not the only reason though.

I listened to Richard Lundgren speak on the topic at a Tech conference a few years ago in Miami, that was one of the reasons for the CCR use. He stated that the use of open circuit on the wreck early on they could see degradation quite quickly. As I remember.

 

[Haaginheimer]

The fathom is just a JJ head on a Meg body with BMCLs.... not an evolution as much as someone taking the best of a bunch of CCRs and cobbling them together.

 

[billgraham]

I'm just a diver but I think that the peculiar environment of the Florida caves has probably influenced rebreather design and configuration a ton.