Multigas Trimix diving computer
Shearwater Perdix AI

The Air Integrated (AI) version of Perdix from Shearwater Research of Canada is a full decompression dive computer with recreational divers in mind. The Perdix AI supports wireless gas pressure integration with tracking tank gas pressures (optional transmitters required.) Out of the box, the Perdix includes open-circuit and closed-circuit Air, Nitrox and Trimix mixed gas functionality along with several enhanced navigation features for the three-axis tilt-compensated digital compass. The standard firmware supports English language menus and both imperial/metric units of measure.

The Perdix AI model with the AI designation has the radio frequency receiver built-in to the electronics. The Perdix AI base price does not include a tank pressure transmitter because the consumer may already own a compatible transmitter.

The Perdix AI is capable of wirelessly connecting to either one or two optional transmitters giving the diver ability to monitor up to two tank pressures and allowing for sidemount diving. It is also capable of calculating the Gas Time Remaining (GTR) on one assigned tank. Air integration is optional for all modes, from OC Rec to CC/BO. The tank pressure(s), in PSI or BAR, and GTR can be displayed to the customizable slots on the main display screen or accessed through the underlying information screens. Enabling the AI feature causes approximately 10% decrease in Perdix battery life.

Will my existing transmitter work with the Shearwater AI computer? Shearwater Research tells us that as long as the transmitter is marked with “FCC ID MH8A” on the body then the transmitter, regardless of the brand, will also work with their Perdix AI, Teric and NERD 2 model air integrated dive computers. However, no other Shearwater dive computer model, including the Perdix model without the “AI” designation and the original NERD, support integration with a pressure transmitter. The first stage regulator tank-pressure wireless transmitter supplied by Shearwater Research is actually manufactured by Pelagic Pressure Systems. Pelagic has been supplying those same OEM transmitters to various dive computer manufacturers such as Aeris, Aqualung, Hollis, and Oceanic for many years.

The Perdix offers an information screen utilizing a large full color LED LCD display. The display will automatically adjust intensity based on available light to make the display easily readable whether on the surface in sunlight, in open water or in a cave. During a decompression dive, the Perdix provides complete information displays of all required stop times. The Perdix can provide time-to-surface based on “look ahead” at planned gas switches. Multiple gas definition presets are supported with any combination of oxygen, nitrogen and helium. The Perdix will NOT “lockout” after a missed stop or ascent rate violation. After the dive, the Perdix communicates via next generation Bluetooth Smart Ready™ with iOS devices such as the iPad and iPhone. In addition to current Shearwater and third party support for Mac and PC desktop applications, users are able to download dives using their iOS devices in conjunction with third party applications. Options include

The Perdix has been designed to accept any type of AA size battery including alkaline, lithium and rechargeable. Included with every Perdix from Dive Gear Express are two elastic straps with buckles, elastic tubing for configuring using the ‘bungee” style wrist mount, zippered hard case, dual o-ring seal gold contact battery door and battery already installed (ready to dive out of the case), two spare battery door o-rings, USB Bluetooth adapter, printed Quick Start Guide with instructions for downloading the full manual and desktop software from the Shearwater Research website. The Perdix also includes a screen protector already installed to help prevent scratches of the display face. The software includes a complete dive log manager, compatible with both MS Windows and MAC OS X. The dive log manager supports log downloads and firmware updates via the Bluetooth wireless interface of the Perdix.

Shearwater supplies the Perdix AI with a zippered “travel” case. The Shearwater travel case included with the Perdix AI is a very snug fit, suitable for dry storage, but not suitable for boat use or damp storage. If you want a well padded case suitable for boat use and with room for extra storage, consider adding the optional DGX Padded Storage Bag.

Recreational Open-Circuit Features
Key features of the Recreational Open-Circuit mode (aka Recreational Nitrox mode) include a simpler menu structure, less cluttered display with a larger font and configurable bottom row, optional safety stops, and a no-decompression limit dive planner. The simplified settings allow for three breathing gas mixtures (Air or Nitrox) and places a greater emphasis on the maximum operating depth (MOD) and no decompression time limit (NDL). The display prominently warns the diver if their depth is near, at or exceeds the MOD of the selected breathing gas. The diver also simply selects one of three levels of NDL conservatism and during the dive a bar graph turns from green to red as the diver approaches the NDL. An optional 3 minute countdown safety stop starts when the diver reaches shallower than { 20 feet | 6 meters } on the ascent. If the diver exceeds the NDL and requires stops, the display turns red and warns “DECO STOP” with the mandatory depth and stop times.