by Jordan Carriveau
The following references some of my experiences during my first Closed Circuit Rebreather (CCR) course that I took in January 2006. We used the O2ptima, Dive Rite’s new CCR. My instructor was Mark Derrick, based out of Ft. Lauderdale, Florida. My open circuit (OC) diving background included: Dive master, Cave, Side mount, DPV, and Trimix diver certifications. I had been diving for more than five years and had around 1,000 total logged dives.
If you have not tried CCR diving yet, you may be nervous and/or skeptical. I admit that I was nervous about diving with a CCR. Attributing factors included real-life stories in the text books of carbon dioxide poisoning, oxygen poisoning, caustic cocktails . . . the list seemed to go on and on. The most repeated phrase was how buoyancy control was very different as compared to OC diving – I had also heard that this was especially frustrating for experienced OC divers. For example, I had heard that new CCR divers often pop to the surface because they can’t control their ascent during the last 15 feet. But to be honest with you, I wasn’t too scared about losing my buoyancy (I have been there, and done that on OC). To me, the really creepy stories were the experienced divers perishing for unexplained reasons. After all, I had zero experience at this point – If they perished, I knew I could too. Further, the anticipation of diving a unit so different from what I was used to, added to my jittery nerves. Sure, I had finished the assigned reading and then some, but the text books just did not instill in me the confidence I would’ve hoped for – I felt like I was missing a lot of basic how-to information. The texts left out a lot of unit-specific information and practical real-world stuff that I knew I still needed to learn. I had hoped that once I got my “fins wet,” that I would start to gain the confidence needed to make CCR diving fun.
Day one started with administrative needs, an orientation and academics. After the first few chapters of academics, it was time to set up the unit for the first time. We went over Mark’s assembly sequence and checklist while setting up the unit. He explained to me why the items were present on the list, and why they were in the particular order that they were in. After completely assembling the unit and performing all of the post assembly checks, I was disappointed to learn that we were just going to break it back down and go back to the academics for the remainder of the day and most likely the majority of the following day.
Day two started right where we left off the night before — scrubber theory and protocol. I must admit, I was getting quite tired of the academic portion by now – I just couldn’t wait to get to the pool and try out this piece of equipment that I have been pawing at and setting up for the last day and a half in the classroom. When we finished up the academics late that afternoon, we were off to the pool. Dipping under the surface for the first time, I almost thought that something was broken because I did not hear the normal whooshing sounds of a regulator (CCR’s are very quiet compared to OC diving, which is actually a reason that a lot of divers choose to dive CCR’s). I began to swim around the pool to get a feel for the new extension of my body and sure enough, there was a difference in buoyancy characteristics, and trim. The counter lungs added a new air space that I was not used to, which needed to be considered when changing depths. I also noticed that if I had too much gas in the counter lungs, my trim (attitude in the water column) would vary, giving me more lift on the top half of my body. What stands out in my mind from the pool session was when I completely flooded the unit. I was to recover the loop by flushing all of the water out of the exhalation counter lung’s over pressure valve in the shallow end of the pool. When I tried for the first time, all I got was a big drink of pool water. After a few tips from Mark, I was able to clear the loop successfully. Although it is difficult to flood the Extendair cannister, I managed to do so this day. I also breathed off of the unit for several minutes just after this full flood, only noticing a slight caustic taste on my tongue. That loop recovery drill quelled quite a bit of my caustic cocktail fear. In fact, this is when I started to believe that this CCR was robust and forgiving enough to be used for cave diving.
Days three through six were all reef and wreck dives out of Pompano Beach, FL. Every morning I was to set up the unit from scratch. On some days, Mark also had me set up his unit, so that I could get more repetitions in and become more familiar with the O2ptima. If you have never dived out of South Florida before, let me say what a luxury it was to have the dive sites so close to the dock. This enabled us to get out in the morning for two dives, come in for lunch and go back out in the afternoon for two more dives. After two days, I was really starting to enjoy the O2ptima, because I finally started to trust the unit. I had the new buoyancy figured out – The trick was keeping my hand near the power inflator, because it is necessary to dump and inject gas more often. At dinner on most nights, we went over numerous what-if scenarios specific to CCR diving. We discussed the important factors that cannot be taken for granted in CCR diving such as dive planning, Oxygen, Carbon Dioxide, O2ptima unit-specific equipment (Hammerhead Electronics). He knew that I would be taking the next course, CCR Tech, so we really hammered emergency procedures and methods in which gas supplies could be extended most efficiently. I began to understand how CCR’s inherently give more options to handle out of gas situations, especially while diving with a competent buddy. Most important, we covered a lot of real-world, practical matters that I just did not get from the assigned readings. In summary, without these late dinners, I seriously doubt that I would have been able to get over a lot of my anxieties so quickly.
Class is over, I am certified, and I am hooked! I dived the O2ptima exclusively for six months without a scare. It wasn’t until I went back to open circuit that I actually got a scare – at one of my favorite dive sites, Pott Springs. Due to the nature of the entrance restriction at the headspring, I had to leave my O2ptima at home and just bring some side mount gear. Sixty minutes into the dive, while swimming in the direction that I thought was the way out, I encountered a line arrow pointing toward the opposite direction! At this moment, the first thought that went through my mind was that I wished I had my O2ptima on, which would’ve given me substantially more time to find the exit. This scenario points out the biggest advantage of diving a CCR in an overhead environment — I have more time to handle potentially deadly situations. When looking at several of the most recent cave diving fatalities, I found that many of these deceased were actually trained and certified to cave dive, however still got lost and/or encountered a problem that caused them to run out of gas. Consequently, if I continue cave diving as avidly (more than 100 cave dives per year) and as aggressively as I do, my CCR just might save my life one day. Hopefully these logbook notes have helped sway you into the direction of trying out CCR diving. Do not be scared of the unknown, for the rewards may be too great to pass up.
Finally, I’ll leave you with some logistical information. Typically, it takes me forty-five minutes to set up the O2ptima for two or three days worth of diving (add five minutes before each dive for double-checks). Post dive disassembly and cleaning takes fifteen minutes. If you are interested in investing in an O2ptima yourself, plan to spend around $10,000 (US). This will take care of the purchase of your unit, your training, your start-up consumables, and other miscellaneous additions to your kit that you will end up wanting, such as bailout cylinders and spare parts.
Side mount butt plate
The side mount butt plate attaches to the bottom of the diver’s backplate extending the backplate lower, like a tail. On each side of this tail are attachment points, which are where the bailout tank’s lower connections snap to. The upper connection points for the bail out cylinders are secured utilizing the second piece of the system, the side mount bungee straps. This fifteen-inch heavy duty bungee has a quick link affixed on one end, which is secured to the top hole on the side of the diver’s backplate. A sliding bolt snap is located on the other end, which is threaded underneath the hoses coming off of the first stage, looped around the cylinder neck, and stretched up to the harness shoulder d-ring and clipped off. Shown on the harness’ waist strap are a knife and the O2ptima Secondary handset pocket.
O2ptima fits in Storm Case
The O2ptima fits in a large Hardigg Storm Case assembled or disassembled. There is enough extra space for additional gear, however not too much so as to allow the O2ptima to move around. The case can be locked and is equipped with wheels, three stationary handles and a pull out handle.
