Shearwater Petrel 3 Wrist Dive Computer

Shearwater Petrel 3: Technical Dive Computer Built for CCR and Advanced Mixed-Gas Diving

The Shearwater Petrel 3 is a wrist-worn dive computer designed for technical and rebreather divers who need a single instrument capable of handling complex gas configurations, closed-circuit monitoring, and deep mixed-gas diving.

If you are pushing into trimix, running a closed-circuit rebreather (CCR), or managing multiple gas switches on long deco dives, the Petrel 3 is built around exactly that kind of diving.

If you are a recreational diver on air or nitrox looking for a clean, simple computer, this is more instrument than you need.

Display and Build

The screen is a 2.6-inch AMOLED panel running at 320 x 240 resolution. AMOLED displays produce deep blacks and strong contrast, which matters when you are reading data at depth in low ambient light.

The lens is toughened aluminosilicate glass, the same family of impact-resistant glass used in demanding industrial applications. The bezel is titanium. These are not cosmetic choices; they are there to keep the screen readable after the kind of contact that happens on serious dives.

Two piezo buttons handle all navigation. Piezo buttons have no moving mechanical parts and no seals to degrade, which is one reason they are preferred on technical computers where reliability at depth is non-negotiable.

Depth Rating and Dive Logging

The Petrel 3 is rated to 290 metres (950 feet). That ceiling covers virtually any technical or CCR dive profile being conducted today.

Dive log storage runs to 1,000 hours of recorded dive time. For a diver doing regular long technical dives, that represents years of logs without needing to offload data.

Diving Modes

The Petrel 3 covers the full range of technical and rebreather diving in a single unit:

• Air / Nitrox for standard open-circuit diving on up to three nitrox mixes.
• OC Technical Trimix enabled by default, supporting up to five open-circuit gases for mixed-gas decompression diving.
• CC/BO Closed Circuit with Bailout manages constant PO2 setpoints for your loop alongside up to five closed-circuit gases, with bailout gas pressure monitoring when air integrated.
• Gauge mode runs depth, elapsed time, and a resettable stopwatch, letting you manage your own profile independently.
• External Monitoring (Fischer port models) provides real-time PPO2 monitoring of one to three oxygen sensors, including support for semi-closed rebreathers.

The ability to run five OC gases and five CC gases simultaneously means the Petrel 3 can handle the kind of complex gas planning that multi-stage technical dives demand.

Air Integration and Rebreather Connectivity

Air integration is standard on the Petrel 3, not an add-on. It supports up to four Shearwater wireless transmitters, so you can monitor pressure across multiple tanks simultaneously, including diluent, oxygen, and bailout cylinders.

For rebreather divers, the Petrel 3 is available in multiple hardware configurations: standalone, DiveCAN, 4-pin AK, and Fischer port models. The Fischer port version adds the external monitoring mode for direct O2 sensor input. Which variant you choose depends on your specific rebreather platform and how you want the computer to interface with it.

Battery

The Petrel 3 runs on a single standard AA battery, and you can swap it yourself without tools or a service centre. That matters on a liveaboard or in a remote location where you cannot predict power availability or wait for a warranty return.

Battery life varies by type:

For most technical dive trips, a lithium AA will cover you comfortably. The Saft option is there for extended expeditions where you want maximum run time from a single cell.

Compass and Alerts

The built-in digital compass is three-axis and tilt-compensated, meaning it stays accurate regardless of wrist angle. It is available in all diving modes, not just surface navigation.

The vibration alert system is strong enough to cut through the tactile noise of a drysuit or thick wetsuit. For a technical diver managing multiple tasks, a wrist tap you can actually feel is more reliable than a tone you might miss.

Connectivity and Logging

Bluetooth connects the Petrel 3 to Shearwater Cloud on PC, Mac, and iOS devices. Dive logs download wirelessly and the interface is available in 13 languages. The computer itself supports ten display languages including English, German, Japanese, Korean, and Spanish.

Shearwater Cloud lets you control how much or how little data you review after a dive. For technical divers who want to analyse gas consumption, decompression profiles, and PPO2 data, the logging depth is there to support that.

Size and Weight

The computer body measures 83 x 75.5 x 39mm and weighs 266g (the external monitoring version weighs 285g). It ships with a ballistic nylon case. These are not small, light dimensions, but the Petrel 3 is not designed for minimalism. It is designed to be read clearly with gloves on, at depth, under load.

Who This Is For

The Petrel 3 is the right computer if you are diving a CCR, planning multi-gas technical dives, or moving into trimix and want a single instrument that will not limit you as your diving evolves.

It is also a serious choice for technical instructors and dive professionals who need a computer that can follow their students into any configuration.

If your diving is open-circuit recreational on one or two gases, the Petrel 3's depth of configuration will go largely unused. There are capable computers better matched to that kind of diving.