TDI and Rebreathers – What is Available?

The choices are many, but TDI™ has something for you!

So you’ve seen them at your local TDI dive center, read about them in diving news or spent some time surfing the internet; what are we talking about? Rebreathers! In particular, Closed Circuit Rebreathers (CCR); they’re all the buzz! Technical Diving International (TDI) heard that buzz in 1995 with the Semi-Closed Circuit Rebreather (SCR), and then again in 2001 with the CCR. Since 1995, a lot of rebreathers have been added to the approved list for TDI training… so many, in fact, that we thought it was time for a review.

Before we get into that review, we thought it might be helpful for you to understand why some rebreathers are not on our list. This is by no means a reflection on any rebreather manufacturer. TDI selects rebreathers based on a few things: production of units, user manual and third party testing. That is just a short list of some of the criteria. We have also never authorized the training on “modified” or “homebuilt” units; why is this? For two of the reasons just listed: there would be no user manual to explain how the unit would work with the modifications or as a home build, and there would be no third party testing. The end goal in everything we do including approving rebreathers is diver safety.

The first SCR in TDI’s course list was the Draeger Atlantis. The first CCR unit TDI ever approved was the Inspiration Classic. These rebreathers, in hindsight, were pretty straight forward and not nearly as sophisticated as today’s units. The Atlantis when first released did not even have a PO2 monitoring device; everything relied on a pre-dive checklist that had to be followed. This was also the case with the original Inspiration, however, it did have two (primary and back-up) monitoring devices for PO2. One thing still remains the same to this day, Pre-Dive checklists are critical to a successful rebreather dive… no exceptions.

TDI now has 13 CCR rebreathers on our list; we have come a long way since 2001:

• Inspiration
• Evolution
• KISS (Classic and Sport)
• Optima
• MK VI Discovery
• Megalodon

• Titan
• Ourboros
• Sentinel
• Pelegian and
• rEvo
• Submatrix

Each of these units has their own unique features and applications, and just like open circuit (OC) equipment, each has to appeal to your personal preference. For the first time in many years, we have also added a new SCR, the KISS GEM, along with three other SCRs that we currently offer training for. SCRs certainly have a place in diving; they’re simplistic, light weight and their ease of use attracts a lot of divers.

We are also very proud to announce that we will be adding two more units to our list the Hollis PRISM II and the Hollis Explorer (an active SCR). The PRISM II is an updated model of the PRISM TOPAZ and is now being built and distributed by American Underwater Products (AUP).

So where does all this leave you, the diver wanting to step into the world of rebreathers? It leaves you in a position with a lot of good choices, but ones that need to be researched, which means you get to do some diving! Most, if not all, of these manufacturers put on events that allow you to try the rebreathers, or you could contact a local TDI rebreather instructor and see if they are putting on a “try dive” for the SCR or CCR they are certified to teach.

Where does this leave the already certified SCR or CCR diver? You are also in a very good place. If it has been awhile since you were certified on a rebreather, you should take a look at the new choices and some of the advancements that have been made. These new machines do a lot more than the earlier models and the monitoring devices – some of them full blown dive computers with decompression information and multi gas capabilities – are amazing.

TDI will continue to stay on the leading edge of this rebreather market, and as we do, we will send announcements for the units we have approved. We will also add them to our course offerings and course search engines so you can find them on our website.

To learn more about TDI™ Rebreather Courses visit /tdi/get-certified/tdi-diver-level-courses/.