I’d been using my Suunto D6i for a few years before upgrading to the Shearwater Perdix AI. Why?
First off, the Suunto tended to be unnecessarily conservative in general. (See the Suunto D6i article for details.) Second, the Suunto doesn’t support trimix, and I anticipate certifying for trimix in the near future. Third, I wanted more control over the decompression algorithm itself, to make the decompression requirements consistent with other technical divers in the area.
Don’t get me wrong—I’ve profited from the Suunto a great deal, and Huck still uses her Suunto D6i silver for recreational diving. We both use the Suuntos for freediving, too. But for technical SCUBA, it wasn’t cutting the mustard.
Shearwater Perdix connected to the wireless gauge.
One of my requirements was wireless air integration.
I’m still at the point where I’m learning about my air consumption, and wanted to be able to analyse SAC rate and consumption patterns automatically. I’m not so concerned with pressure during the dive, as I’d only check from time to time anyway. But even for that, it helps not to need to unclip from my hip ring each time I want to check.
Shearwater Perdix and its wireless gauge in evidence.
I initially tended toward an OSTC because they’re more open source
friendly; and as somebody who uses an exclusively open source stack,
this appeals to me.
However, when looking at the new OSTC4, this turned out not to be the case—and the OSTC4 doesn’t have air integration.
The OSTC2 TR does, but the screen is fairly small. The price was roughly equivalent for the TR—maybe it was a bit cheaper.
All things being equal, I took the one that was less bulky.
Shearwater Perdix and wireless gauge in action.
A few dozen decompression and recreational dives in, with up to three mixes (back gas, travel gas, rich gas; though only two with the wireless), I have no complaints. The only nit I know of is being able to configure the display to show both a timer (for planned decompression stops) and the wireless pressure gauge. Perhaps I just haven’t figured out the correct options to select. I do think I’ll end up getting a short hose for the integrated air, as it sometimes hits the back of my head. But that’s the fault of my rigging, not the Shearwater.
Also note that the Perdix doesn’t have a freedive mode, so I continue to use my Suunto D6i for that.
Oh—if you use a system that doesn’t have Bluetooth LE support, like mine, you may need to jump through some hoops to get your data into Subsurface or divecmd. I end up using my Android phone to download the dives into Subsurface mobile, sync to cloud, then edit on my desktop. Whew!