By Michael Menduno
Header image of the author, Capt. Mark Nease and Capt. Billy Deans at Key West Diver, Stock Island, FL before p-valves were invented (1992). Photo by Dan Burton.
“To pee, or not to pee?” is NOT a question for tech divers. With the possible exception of British expat picture-maker extraordinaire, Tom St. George—who swears he never pees underwater in a drysuit—good hydration and long dives dictate that the urine will flow. The question is, how are you going to deal with it? [Obviously, easy peezy for wetsuit diving—just let it wizz.]
Today, of course the solution de rigueur for drysuit diving is the condom catheter and a p-valve for men—just slide on the sheath, connect it to the one-way p-valve hose, and you’re good to go. Women commonly use the She-P external catheter or the Shewee Go, which is a little more complicated, or resort to diapers. Problem solved! For the most part anyway. However, it turns out that might not always be the case, as I discovered on my recent diving trip to Mexico.
A Wee Bit of History
Male commercial divers enjoyed the privileges of an in-water urinary solution as early as 1876. By 1909, legendary British equipment manufacturer Siebe Gorman & Co Ltd. was touting its “Portable Rubber Urinal” in its catalog. According to the entry, the pouch-like device, which is attached to the male diver by means of a belt, was so constructed that “The diver can urinate without fear of the urine entering his dress, no matter what position he may be working.” Urine was captured in a tube with a non-return valve and emptied at the end of the job. The accompanying dry suit featured a watertight metal port with a screw-down plug enabling the diver to pee without undressing. Unfortunately, it took the sports diving industry a bit longer to get on with it.
Ironically, early dry-suited cave divers—predecessors of today’s tekkies—were slow to heed the call of nature. According to underground graybeard Paul Heinerth, who was a member of Bill Stone’s original 1987 Wakulla Project, “We would just hold it till we were in the deco habitat and pee through the doorway in the water just before changing depth as it would act as a flush.” And these were long decompression dives to depths between 75-100 m/244-326 ft.
Adult diapers were available but not regarded as an acceptable solution. I once asked the late great underwater filmmaker, Wes Skiles, who was also at Wakulla, about his urinary practices for a story that I was researching, “Us manly men were too stupid and/or too embarrassed to slip on diapers,” he sheepishly admitted. Underground patron saint Sheck Exley, also on the project, used a wet suit supplemented with chemical heaters, or his red Parkway neoprene drysuit, where he could “just cut it loose” for extended cave dives.
Diapers, aka nappies, briefly came into vogue in the early 1990s as tech diving was just emerging from the closet. Explorer Jim King and his team began using diapers on their 1991 Diepolder #2 Project. So did tech pioneer Capt. Billy Deans and his Key West Divers team on deep wreck dives (Full disclosure: I was a member of Dean’s team and we used “Depends”).
P-valves with male condom caths made their debut in the mid-to-late 1990s. “A few of us were playing with homebuilt designs,” GUE founder and president Jarrod Jablonski explained to me. “[Early cave explorer] Roger Werner is also one that comes to mind. He was building some of his own and essentially selling them to others.” In the early days of cave diving, it was not unusual for divers to make their own gear.
According to Jablonski, Extreme Exposure dive centre based in High Springs, FL was the first to commercially produce and distribute p-valves back in the late 1990s. Production was soon moved to Halcyon Dive Systems (Ed.—Jablonski is a co-owner of both). As a result, the relief zipper—remember them?—became a thing of the past.
At the time, female tech divers were stuck with diapers or nothing at all. That is until Netherlands DIR (“Doing It Right) diver Heleen “Wethorse” Graauw, invented the first underwater female catheter system, which Fred Devos, cave explorer and co-owner of Zero Gravity in Puerto Aventuras, Mexico, dubbed the “She-P” when Graauw visited Mexico, and the name stuck. She-Ps mostly do too, thanks to help of ex-surgical tech Laura James, who teamed up with Graauw to perfect the adhesive system and distribution. Another external device on the market is the Shewee Go. For more information see: Urination Management Considerations for Women Technical Divers by Payal Razdan in InDepth V 1.9.
The Joys of Nappies
Condom caths and p-valves work great for men except when they don’t. Assuming that your p-valve is functioning and properly maintained, the condom may refuse to stay in place. Which brings us back to Mexican cave diving.
As anyone who has dived Riviera Maya during the spring or summer months knows, the air is hot and humid. As a result, your entire body stays dripping wet, before, during, and after you get in the water. The result? Much to my chagrin, on our first couple of dives, my condom refused to stay on. As they say, “No glove, no love.” My p-valve was definitely NOT showing me any love. We’re talking spillage. What to do?
I consulted with tech and cave instructor Kelvin Davidson, proprietor of Third Dimension Diving in Tulum, who offered a couple of solutions. Option one: buy condoms two sizes too small (Davidson buys “Ls.” Wreck diver! ), and be prepared to stuff your junk. Option two: purchase a bottle of rubbing alcohol and pads, wipe your willy after your morning shower, and put on your condom before the humidity gets out of hand.
Instead, I opted to go old school. I walked down to the local farmacia and bought a twelve-pack of high tech (gel-based) adult diapers for US$8. They even featured rip-away sides for easy removal post-dive. Yeah, I had to put up with some ribbing from the guys, but I happily dived nappies for the rest of the trip with just a hint of nostalgia. More importantly, I didn’t have to worry about slippage! (Full disclosure: I peed twice on some dives. Well, OK, two and a half times.It was not a problem). As they say in GUE circles (usually when they are referring to rebreathers or sidemount configuration), “The right tool, for the right job!”
InDepth: Urination Management Considerations for Women Technical Divers by Payal Razdan
Diver: The Divine Secrets of the She-P Sisterhood by Michael Menduno
Michael Menduno/M2 is InDepth’s editor-in-chief and an award-winning journalist and technologist who has written about diving and diving technology for more than 30 years. He coined the term “technical diving.” His magazine aquaCORPS: The Journal for Technical Diving (1990-1996), helped usher tech diving into mainstream sports diving and he produced the first tek.Conferences and Rebreather Forums 1.0 & 2.0. In addition to InDepth, Menduno serves as an editor/reporter for DAN Europe’s Alert Diver magazine, a contributing editor for X-Ray mag, and writes for DeeperBlue.com. He is on the board of the Historical Diving Society (USA), and a member of the Rebreather Training Council.
InDepth’s Holiday Rebreather Guide: 2022 Update
Making a list. Checking it twice. Gonna find out which breathers are naughty or nice. That’s right! It’s time again for InDEPTH’s Holiday Rebreather Guide.
This year, the Guide features 28 models of back, chest, and side-mounted rebreathers, including two new entries, for your shopping operation. So, get out your pre-buy checklist, and that gift certificate and start ogling your loop of your fancy. Ho ho ho!
by Michael Menduno, Amanda White and Kenzie Potter
Holiday images by Jason Brown, BARDO CREATIVE
A Guide to Backmount, Sidemount and Frontmount Rebreathers
1DEC 2022—Ho ho ho! Once again, we have updated InDEPTH’s Holiday Rebreather Guide adding two new rebreathers; the new Gemini sidemount, needle valve mCCR from Fathom Systems, and the Generic Breathing Machine (GBM) front mounted, needle valve mCCR, with a dive computer-compatible, solid state oxygen sensor from Scubatron. We also updated the features on the Divesoft Liberty sidemount, and the JJ-CCR. This year, Vobster Marine Systems was acquired by UK-based NAMMU Tech, which plans to rename and re-issue a version of the VMS Redbare. See link below.
Finally, Innerspace Systems’ founder Leon Scamahorn agreed to work on getting us the needed information to add the storied Megalodon to the Guide. Scratch last year’s coal, Xmas cookies for you Mr. Scamahorn! Happy holidays shoppers, here is our updated rebreather guide! Mind those PO2s!
17DEC2021: Ho Ho Ho! We have updated our Holiday Rebreather Guide with new rebreathers and updated features. Despite repeated requests, the only major closed circuit rebreather we are missing is Innerspace Systems’ Megalodon and its siblings. Tsk, tsk Leon Scamahorn, you’ve been a naughty boy! Behold, here is our updated guide. Mind those PO2s!
Sport diving rebreathers have come a long way since storied explorer Bill Stone trialed his 80 kg/176lb fully-redundant “Failsafe Rebreather For Exploration Diving” (F.R.E.D.), and spent a cool 24-hours underwater as part of his paradigm-shifting 1987 Wakulla Springs Project. In retrospect, looking back over the last 30-some years, the “Technical Diving Revolution,” which emerged in the late 1980s to late 1990s, was ultimately about the development and adoption of rebreather technology.
However, it took the fledgling tech community at least a decade to adapt mixed gas technology for open circuit scuba, including establishing the necessary supporting infrastructure, which was the first and necessary step in the move to rebreathers. A little more than a decade after Stone showcased FRED, British diving entrepreneur Martin Parker, managing director of then AP Valves, launched the “Buddy Inspiration,” the first production closed circuit rebreather designed specifically for sport divers, earning him the moniker, the “Henry Ford of Rebreathers.” [The brand name later became AP Diving] KISS Rebreathers followed a little more than a year later with its mechanical, closed circuit unit, now dubbed the KISS Classic. The rest as they say, is history, our history.
Today, though open-circuit mixed gas diving is still an important platform, rebreathers have become the tool of choice for deep, and long exploration dives. For good reason, with a greatly extended gas supply, near optimal decompression, thermal and weight advantages, bubble-free silence, and let’s not forget the cool factor, rebreathers enable tech divers to greatly extend their underwater envelope beyond the reach of open circuit technology.
As a result, divers now have an abundance of rebreather brands to choose from. Accordingly, we thought it fitting this holiday season to offer up this geeky guide for rebreather shoppers. Want to find out whose breathers are naughty or nice? Here is your chance.
Your Geeky Holiday Guide
The idea for this holiday guide was originally proposed to us by Divesoft’s U.S. General Manager Matěj Fischer. Thank you Matěj! Interestingly, it doesn’t appear to have been done before. Our goal was to include all major brands of closed circuit rebreathers in back mount and sidemount configuration in order to enable shoppers to make a detailed comparison. In that we have largely succeeded. We also included Halcyon Dive Systems’ semi-closed RB80 and more recent RBK sidemount unit, which are both being used successfully as exploration tools.
Absent are US-based Innerspace Systems, which makes the Megalodon and other models, as well as Submatix, based in Germany, which manufactures the Quantum and sidemount SMS 200, neither of which returned our communications. M3S, which makes the Titan, declined our invitation to participate, as they recently discontinued their TITAN CCR—they will be coming out with a replacement unit, the TITAN Phoenix CCR in the near future. We did not include the MARES Horizon, a semi-closed circuit rebreather that is aimed at recreational divers. No doubt, there may be brands we inadvertently missed. Our apologies. Contact us. We can update.
Update (22JUL2021): French rebreather manufacturer M3S contacted us and sent us the specs for their updated chest-mounted Triton CCR, which are now included in the guide.
Update (9DEC2020): Submatix contacted us and the Guide now contains their Quantum (back mount) and SMS 200 (sidemount) rebreathers. We were also contacted by Open Safety Equipment Ltd. and have added their Apocalypse back mounted mechanical closed circuit rebreather. We will add other units as they are presented to us by the vendors.
It’s The Concept, Stupid
The plan was to focus on the feature sets of the various rebreathers to provide an objective means to compare various units. But features by themselves do not a rebreather make. As Pieter Decoene, Operations Manager at rEvo Rebreathers, pointed out to me early on, every rebreather is based on “a concept,” that is more than just the sum of its features. That is to say that the inventors focused on specific problems or issues they deemed important in their designs; think rEvo’s dual scrubbers, Divesoft’s redundant electronics, or integration of open and closed circuit in the case of Dive Rite’s recently launched O2ptima Chest Mount. Shoppers, please consider that as you peruse the various offerings. My thanks to Pieter, who helped us identify and define key features and metrics that should be considered.
Though not every unit on the market has been third-party tested according to Conformitè Europëenne (CE) used for goods sold in the European Union, we decided to use CE test results for some of the common feature benchmarks such as the Work of Breathing (WOB), and scrubber duration. For vendors that do not have CE testing, we suggested that they use the figures that they publicize in their marketing materials and asked that they specify the source of the data if possible. As such, the guide serves as an imperfect comparison, but a comparison nonetheless.
Also, don’t be misled by single figures, like work of breathing or scrubber duration as they serve only as a kind of benchmark—there is typically a lot more behind them. For example, whether a rebreather is easy to breathe or not is a function of elastance, work of breathing (WOB) and hydrostatic imbalance. In order to pass CE, the unit must meet CE test requirements for all three issues in all positions from head down, to horizontal trim, to being in vertical position (Watch that trim!), to lying on your back looking upwards. It’s more difficult to pass the tests in some positions versus others, and some units do better in some positions than others.
The result is that some of the feature data, like WOB, is more nuanced than it appears at first glance. “The problem you have is people take one value (work of breathing for instance) and then buy the product based on that, but it just isn’t that simple an issue,” Martin Parker explained to me. “It’s like people buying a BCD based on the buoyancy; bigger is better, right? Wrong! It’s the ability of the BCD to hold air near your centre of gravity determines how the BC performs. With rebreathers you can have good work of breathing on a breathing machine only to find it completely ruined by it’s hydrostatic imbalance or elastance.”
Due to their design, sidemount rebreathers are generally not able to pass CE requirements in all positions. Consequently, almost all currently do not have CE certification; the T-Reb has a CE certification with exceptions. However, that does not necessarily mean that the units haven’t been third-party tested.
Note that the guide, which is organized alphabetically by manufacturer, contains the deets for each of their featured models. In addition, there are two master downloadable spreadsheets, one for back mounted units and one for sidemount. Lastly, I’d also like to give a shout out to British photog phenom Jason Brown and the BARDOCreative Team (Thank you Georgina!), for helping us inject a bit of the Xmas cheer into this geeky tech tome [For insiders: this was Rufus and Rey’s modeling debut!]. Ho, ho, hose!
With this background and requisite caveats, we are pleased to offer you our Rebreather Holiday Shoppers’ Guide. Happy Holidays!!
Ed. note: Most prices shown below were specified by manufacturer before tax.
Download our two master spreadsheets, one for back mounted units and one for sidemount to compare rebreathers.
Special thanks to Amy LaSalle at GUE HQ for her help assembling the feature spreadsheets.
Michael Menduno is InDepth’s editor-in-chief and an award-winning reporter and technologist who has written about diving and diving technology for 30 years. He coined the term “technical diving.” His magazine aquaCORPS: The Journal for Technical Diving (1990-1996), helped usher tech diving into mainstream sports diving. He also produced the first Tek, EUROTek, and ASIATek conferences, and organized Rebreather Forums 1.0 and 2.0. Michael received the OZTEKMedia Excellence Award in 2011, the EUROTek Lifetime Achievement Award in 2012, and the TEKDive USA Media Award in 2018. In addition to his responsibilities at InDepth, Menduno is a contributing editor for DAN Europe’s Alert Diver magazine and X-Ray Magazine, a staff writer for DeeperBlue.com, and is on the board of the Historical Diving Society (USA)
Amanda White is the managing editor for InDepth. Her main passion in life is protecting the environment. Whether that means working to minimize her own footprint or working on a broader scale to protect wildlife, the oceans, and other bodies of water. She received her GUE Recreational Level 1 certificate in November 2016 and is ecstatic to begin her scuba diving journey. Amanda was a volunteer for Project Baseline for over a year as the communications lead during Baseline Explorer missions. Now she manages communication between Project Baseline and the public and works as the content and marketing manager for GUE. Amanda holds a Bachelor’s degree in Journalism, with an emphasis in Strategic Communications from the University of Nevada, Reno.
Kenzie Potter Stephens is a production artist for InDepth as well as part of the GUE marketing team. She earned her BS degree in Industrial Engineering and Marketing at the Karlsruhe Institute of Technology (KIT) in Germany, which assists her in using her multicultural upbringing to foster international growth within the community. In addition to her activities as a yoga teacher and an underwater rugby trainer, she has completed her GUE Tech 1 and Cave 1 training and is on her way to becoming a GUE instructor. Not letting any grass grow under her feet, she has also taken on a second major in biochemistry in order to create a deeper understanding of our planet’s unique ecosystems as well as the effect of diving on human physiology.
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