Choptima Updates

The Dive Rite O2ptima CM (choptima) has had several updates and upgrade offerings since its release in 2020. I put together a summary of these changes to help divers who purchased a unit years ago, are looking at used units, or are interested in upgrading a new unit with fancy bits. This page isn’t endorsed by Dive Rite and I cannot guarantee it’s complete – it’s just a best effort to summarize many years of updates.

Counterlungs

The original version (2020) was released with 5L counterlungs. Newer, larger lungs (6L size) were released in 2021 and the current lung size is 6.4L. This increase in volume helps people with larger lungs and decreases the unit work of breathing (WOB). The new lung versions are also less prone to flange-related leaks. During annual service, the lungs are inspected and replaced if they show signs of wear. The 6.4L size is included with new units. To determine the size of your lungs you need to have a qualified service tech or Dive Rite remove and inspect the lungs.

Exterior bag

The exterior bag has been upgraded a few times. The original bag (2020) accommodated the smaller-size counterlungs and did not have an integrated line cutter. Later the line cutter bag was introduced and the newest version is the large bag. The bag logo has also changed a few times. The newest bag increased the width of the bag by ~1/2in for full utilization of the 6.4L lungs. The line cutter included on the exterior bag is not standard. The hook/loop is reversed on the choptima line cutter and is a special order item. New units come with a line cutter but this is important information if you lose yours and need to replace it.

Scrubber Tower Connections

The original tower connectors were the same as the loop connectors – small, thin silicone o-rings and hand-threaded circular-shaped fittings. Dive Rite upgraded the scrubber connectors in 2022 to use a thicker/larger buna o-ring and large, knurled fittings. These changes increase the ease of assembly and reduce the chances of rolling o-rings. If – somehow – your unit has the original attachments they should be upgraded during annual service to the knurled tower nuts.

Locking Quick Disconnect (QD)

The low pressure inflator (LPI) from Ovygten to y-block was originally a standard hose with a lockout clip. In 2023 this was upgraded to a new fitting created for this purpose. The upgrade reduces the chances of a faulty lockout clip and easily attaches a standard regulator LP hose. It’s a lockout ring and low pressure quick disconnect integrated. This should be upgraded on all older units and ships as stock now.

Petrel 3

When shearwater upgraded from the Petrel 2 to Petrel 3 Dive Rite followed suit. The Petrel 3 has a better display (easier to read at different angles) and haptic feedback (it vibrates when something is wrong). Petrel 2s are still functional and don’t need to be upgraded, but the 3 is better.

Sensor Tray Thumb Screw
In 2024 dive rite began replacing the Phillips head screw that attaches the sensor tray with a screw that can be hand-turned. This screw fits best on thicker sensor trays.

Watertrap

The water trap and anti-collapse tubes used to be the same white tubes but were replaced with a black water trap and a white anti-collapse tube. The change happened in 2020/2021. The black watertrap is more effective.

DSV

The earliest production DSV was replaced early in the O2ptima CM's life. The old-style DSV had larger bayonet fittings, a lever located closer to the chin, and a large engraved logo near the top. The older models had different hud mount styles as well.

Sliding Boltsnaps

These sliding boltsnaps are the unit’s right/left lower attachments. They are designed to be easy to clip and then quick to tighten. The original version was 3D printed and now they are molded. These items are now stock on new units.

Scooter ring

This is the center lower attachment for the unit that also serves as a mounting point for a scooter tow leash. The center mounting point is crucial for a snug fitting and comfortable choptima.

QC6 Diluent attachment

This is an optional upgrade that changes the Diluent fitting from a standard LPI QD to a QC6 fitting. The QC6 offers benefits over the LPI, namely dry-connect and higher flow. The higher flow volume has proven better for deep-diving applications. The QC6 is also a standard for some team-diving applications. To accommodate the QC6 a specialty 6in female-to-female low pressure hose is added. This gives the user a better grip to lock the QC6 into place. The downside to QC6 is cost and bulk.

Diluent Manual Add Valve (MAV)

The Dil MAV replaces the Automatic Diluent Valve (ADV) with a push-button interface. Some people prefer this setup because it eliminates the slider and the ADV. As the name implies, it requires manual intervention to inject diluent. This is a great option for users who don't like the ADV's functionality.

Pull dump OPV

The OPV/dump is used to vent gas from the unit in the event it’s over pressurized, you have bailed out, or need to de-water the unit. The stock dump is a standard drysuit dump valve. The upgraded pulldump is smaller, better, and easier to use.

Skid Plate

The skid plate protects the lower part of the bag which is prone to tears - especially the outside seam. This protector is great and I recommend it. A common misconception is that the skid protector is only for cave/wreck/bad divers (or a combination of any 3). It provides the most value to me at the surface where the unit can take a beating going in and out of trucks, boats, etc.

NERD Dual Mount

The stock NERD unit comes with the NERD and mounting hardware with no way to secure the standard HUD. The protocol is typically to stuff the HUD into the bag and then deploy it if needed to monitor PO2. Dive Rite sells a dual mount so both HUD and NERD can be seen at the same time. This offers advantages - like making the HUD visible and useful. Even with a NERD, the simple blinky-light HUD is useful in low-visibility and high-stress situations.

A full equipment list for CCR class is here, but in general, these are the required and suggested upgrades.

Required upgrades/accessories

• Scooter ring center attachment point
• Sliding Boltsnaps (x2) (stock on new units)
• Bag Protector aka skid plate
• CM pull dump valve
• Counterlung cleaning caps set
• Dual nerd HUD holder (if using NERD)
• 13cuft cylinder for onboard oxygen
• Extendair cartigrades 4 pack
• Microfiber towels

Optional items:

• Low Profile fixed d-rings for upper attachment (x2)
• Sliding d-rings for waist attachment (x2)
• Choptima Save-a-dive kit
• Vortex Optics Defender Riflescope Flip Caps - 24mm for NERD to replace stock cover. (if using NERD)

Stock units come with:

• Rebreather
• Oxygen regulator (tuned to 90psi with special spring)
• 4 sensors
• Trilube 71
• Steramine tablets
• User manual
• Extra filter scrims
• Calibration caps
• Line cutter