A rebreather is a significant investment, and good rebreathers like the JJ-CCR are very robust. This means that—with a little luck—it’s possible to buy a lightly used rebreather and use it for a long time. However, there are some important points to consider when going used vs. new.

The JJ-CCR has been available since 2006, and was in testing for many years before that. The design has gone largely unchanged, and as a result the unit is extremely reliable and the failure modes that do exist are well understood. However, there have been several major changes that have occurred since the unit was first introduced that a buyer of a used unit must understand before purchase.

The oldest version of the JJ-CCR is often known as an “analogue” unit, as the electronics onboard were hardwired in place, and used a non-digital mode of communication. While this unit was very functional, the non-digital communication between the handset, controller, and HUD made it difficult to repair. Furthermore, damage to cabling could lead to erroneous communication between components of the rebreather. Analogue JJ-CCR units are no longer supported by the manufacturer, and therefore will not be allowed in class. These units are often available for extremely low prices as a result of the fact that repairs are difficult or impossible. You should not buy one of these units for a GUE course.

Analogue units can be most easily identified by their HUD, which is made of black plastic rather than transparent plastic. The analogue JJ-CCR also has a metallic silver button on the top of the the rebreather head. A modern JJ-CCR does not have this button. Note that all JJ-CCR units have a black button on the side of the rebreather head. An analogue unit cannot be upgraded to a modern version, should not be purchased, and will not be acceptable for use in class.

Petrel 2 Equipped JJ-CCR

Although analogue units are still available on the used market, they’re becoming increasingly less common. More recently, the JJ-CCR has been upgraded to use a Petrel 3 handset rather than the older Petrel 2. It is very difficult to tell the two apart, but it is possible by checking in the settings or by looking at the side buttons: a Petrel 2 has black side buttons. A Petrel 3 has metal colored side buttons.

The Petrel 2 is discontinued, and only a small number of spare parts are available—no more spare parts will be manufactured. Although Shearwater electronics are durable, mistakes happen as do failures. The most likely result of a failed or damaged Petrel 2 incident is that you will need to buy a brand new Petrel 3. All modern JJ-CCRs (including those originally equipped with a Petrel 2 or 3) use digital communications via DiveCAN, which allows for easy exchange of components.

A JJ-CCR with a Petrel 2 is acceptable for use in class. However, you should budget for a Petrel 3 when you are making a decision on a used unit. A damaged Petrel 3 can often be repaired inexpensively. A damaged Petrel 2 will generally need to be replaced with a Petrel 3 controller at a cost of approximately $1,600 plus shipping and tax.

I would recommend against buying a used JJ-CCR equipped with a Petrel 2 unless it is such a good deal you can buy the used unit and a Petrel 3 and still come in at a reasonable price point.

It is difficult to tell how a unit has been treated. If you buy a used JJ-CCR, you will need to have it professionally maintained prior to class. This is a service that is available in many places around the world, including Eight Diving. Please factor the cost of a unit overhaul into the cost of the unit you are purchasing. You will not be allowed to dive a used JJ-CCR that has not been professionally maintained before class.

With these points in mind, it is still possible to get a good deal on a used unit:

- Ensure the unit is a modern JJ-CCR, not an analogue unit.

- Consider if you are willing to buy a unit equipped with a Petrel 2, and factor the cost of a replacement handset into the cost of the unit.

- Contact a professional service center and factor the cost of a overhaul into the cost of the used unit.

- Ensure the overhaul can be completed prior to class.

- Prefer low-hour units (100 hours or less). Avoid units with over 1,000 hours on them: a rebreather has soft parts that will break down and fail.

- Ensure you are still getting a good deal on a used unit—often a new unit will be only marginally more expensive and will be under warranty as well.