CCR's - Pro's & Con's

March 06, 2020 • Leave a Comment

Closed Circuit Rebreather (CCR) vs Open Circuit (OC)

Friends of mine who have ventured down the road of closed circuit rebreather (CCR) use are universally asking me when I will get certified on a unit. I have been debating doing so for several years but have yet to pull the trigger. Even though I have been an Open Circuit (OC) diver since 1980 and a trimix diver since 2003, I have resisted the temptation of crossing over to CCR. This blog lays out the Pro's & Con's that are fostering my debate.

Closed Circuit Rebreathers (CCR) have advanced greatly in the past 35 years since I became a recreational diver. (For the layperson reading this, please refer to the link above for an explanation of CCR diving). I'm seeing more and more units appear on the boat I captain, the M/V Odyssey in Truk Lagoon. Truk is an ideal place to practice CCR diving due to the more challenging depths and the rebreather friendly atmosphere of the Odyssey. CCR is a logical path to go for the recreational diver who wants to push their training and experiences further. I believe that the decision to go this route should not be taken lightly. CCR diving has serious inherent risks that go beyond recreational OC diving and one should have all the facts before delving in. Maybe this blog will assist you in your decision making.

San Francisco Maru Depth Charges Pro's

•Increase bottom time while decreasing deco. As a professional photographer, this simply says that I have more work time in the water per dive on CCR without incurring excess deco. This equates to accomplishing more in one dive on CCR that I could in two or more dives on OC. More work time = more photos = increased livelihood. This is at the top of my pro's list and the primary reason that I would crossover.

•Savings on gas consumption. The basic concept of recycling your gases with a CCR means consuming less O2 and expensive trimix compared to OC diving. The savings could be as much as 75% equaling hundreds of dollars saved or even thousands per expedition depending on depths and number of dives conducted.

•Accessing deeper dives. It can be debated whether it is safer to do 300'+ dives on OC vs CCR. I will point out that at those depths and run times you will be carrying less gas and bottles on CCR vs OC which means less drag in the water and more maneuverability and less chance for error with gas switches. This is an important factor as a photographer when I'm already carrying a large camera housing with added task loading. My motto is minimalism and CCR's can offer that for deep diving. If you desire to explore deeper CCR could be the way to go. Most of the diving I do is less than 200' so CCR's are not crucial to reach those depths.

•Silent factor. CCR's eliminate noise from venting bubbles as with OC. This is beneficial to accessing closer proximity to marine life that are normally skittish around OC divers. Getting closer is the name of the game with underwater photography. Closer could yield more impactful images.

Hoki Maru Con's

•Time. Will you be diving with CCR friendly operators that permit extended bottom times that CCR's make possible? As for me, the answer is mostly no. As a liveaboard captain, I believe that it is not a prudent practice to be off the boat more than an hour or so. If I didn't get the shots I needed on one dive I will be back the next week and the week after that etc. There is usually no stress or shortage of opportunities to collect my images.

•Maintenance. This is related to the time factor. Just ask any responsible CCR diver and they will tell you that CCR units require diligent time consuming maintenance. Packing and repacking scrubber, checking sensors, repairing micro-leaks. etc etc. I see CCR divers tinkering with their gear more than OC divers hands down. However, they are a hi-tech piece of equipment that warrants this level of care.

•Discipline. Are you disciplined enough to use a CCR? I'll vouch that there are Control Room Reiyo Maru
many who are not. Complacency is potentially the primary cause of injuries and fatalities with CCR divers (a debatable topic). Diving CCR requires abiding by serious pre-dive checks that are more intense than the standard OC buddy check. I've been witness more times than I care CCR divers doing inadequate or non-existent checks and even by-pass carrying bail-out bottles. This is a recipe for disaster. As a photographer, I can vouch that the task loading of taking UW imagery pulls my attention away from monitoring my life support. CCR diving requires upmost due diligence; more so than OC and I wonder if I will become another statistic due to my photography distractions.

•Cost. CCR units and training are expensive. You can buy used units or the cheaper models but do you really want to skimp on a hi-tech piece of life support equipment? Do you want to shop around for the cheapest instructor. Not this guy. When all is said and done add another $10,000-$15,000 to your credit card bill. That is a piece of change the average photo pro and dive boat captain just doesn't have laying around. If I could justify it as a business expense, the cost would become less of a concern.

Reiyo Maru Skylight