Garmin Descent vs Shearwater

[scrane]

I have a Perdix and a Descent MK1. I dive with the Shearwater on my left wrist and the Garmin as backup on my right. They track perfectly with each other and share many features. The Garmin has never failed and I have grown to trust it over the four years I've had it. It is also a very capable sports watch that I mostly use for hiking with its GPS capabilities.

 

[TxDivN13]

well that got interesting...
I let a quality decompression software calculate my deco obligation.

 

[TxDivN13]

I have a Perdix and a Descent MK1. I dive with the Shearwater on my left wrist and the Garmin as backup on my right. They track perfectly with each other and share many features. The Garmin has never failed and I have grown to trust it over the four years I've had it. It is also a very capable sports watch that I mostly use for hiking with its GPS capabilities.

I agree, the Garmin is very dependable.
thanks for the input.

 

[ginti]

Instead of no deco we've been doing min deco ascents which is a stop at 50% and every 10ft thereafter. I haven't found a way to make my Garmin aware of this, so I either use gauge mode or just disable it's safety stop alert.

Hi @sourdough, it sounds like you have GUE training, am I right?

I believe there is no computer in the market customisable in that way (I may be wrong, though), and I do not see any reason why they should. The purpose of a diving computer is NOT to tell you when or how to stop. (Over-) Simplifying, their goal is to calculate the "saturation level" at any dive moment.

By the way, that minimum deco procedure is typical only of some (one?) agencies, and it is absolutely NOT necessarily the best way to do all the stops (sometimes you do not even need to stop).

 

[ginti]

I agree, the Garmin is very dependable.
thanks for the input.

I have a Descent mk1. I do not regret my purchase, because with the money for a good trimix computer I also have a high-quality sport-watch (which I need). But, if I had to buy something only for diving, it would be a Perdix. Maybe I could evaluate an Odyssey, but for sure, not a Garmin. Indeed, both versions of the mk2 are too small compared to other computers.

 

[Belzelbub]

I have the Garmin Descent MK2i with transmitter. Ive had it for about a year but not really liking it lately. Feels too big for running and too small for diving.
And thoughts on Descent MK2i vs Shearwater PerdixAi.
Diving lakes, caves, tec and SCR.

I think you've pretty much summed it up. Both the Garmin and the Shearwater use the same algorithm, so they should be fairly close. The main benefit of the Garmin is the Smartwatch and other activity tracking. The Perdix doesn't have a freedive mode, though not sure if that matters to you.

The Perdix screen is great. Easy to read and easy to configure. From a UI perspective, the Shearwaters are tough to beat.

The Shearwaters use the common PPS transmitters (Oceanic, Aqualung, etc.) as well as the Swift. The Garmin uses a proprietary transmitter. On paper, the Garmin transmitter sounds superior. In practice, maybe not so much. The range for the Garmin transmitter sounds impressive, but my arms aren't long enough to make a difference. I'm also not a fan of the transmission protocol switching above and below the water. Makes it so that you can't really tell it's working in dive mode until you are in the water.

I plan on adding a Descent to my kit. Mainly to add Smart/activity functions as well as having a backup, but it will be one of the smaller ones. Just trying to figure out if it will be the MK2s or G1.

 

[Nick_Radov]

Instead of no deco we've been doing min deco ascents which is a stop at 50% and every 10ft thereafter. I haven't found a way to make my Garmin aware of this, so I either use gauge mode or just disable it's safety stop alert.

What does that even mean? The Descent Mk2 is "aware" of your depth and time. You can run whatever ascent profile you like, and it will give you an estimated deco ceiling as per the ZHL-16C algorithm. You can configure the gradient factors, last stop depth, and whether it alerts you to do an (optional) safety stop.

If you want the computer to tell you to stop at 50% of max depth then just set the GF Low value to something like 10. But the reality is you are still on-gassing at that depth, and stopping that deep is probably not beneficial. The GUE Rec 2 (Triox) course materials do still recommend making the first stop at 50% and then every 10ft thereafter, but those slides were last updated in 2017 and I don't think they match current recommendations.

Gradient Factors in a Post-Deep Stops World

World-recognized decompression physiologist and cave explorer David Doolette explains the new evidence-based findings on “deep stops,” and shares how and why he sets his own gradient factors. His recommendations may give you pause to stop (shallower).

gue.com

I know how to calculate my own deco plans so I'm fine with running my Descent Mk2 in gauge mode. But usually I do run it in computer mode just to provide a cross-check on my own calculations. I don't necessarily follow what the computer tells me to do, but if it shows me a deco ceiling or TTS significantly different from what I think it should be then that's a good signal to take a moment and assess what's happening.

 

[SFLScubapro]

I have the Garmin Descent MK2i with transmitter. Ive had it for about a year but not really liking it lately. Feels too big for running and too small for diving.
And thoughts on Descent MK2i vs Shearwater PerdixAi.
Diving lakes, caves, tec and SCR.

I have both the Perdix and the Garmin Descent Mk2i (with transmitter) and hands down prefer the Perdix. I am a technophile, so truly like enjoy trying out new toys. The Descent has an annoying feature, a BEEP every 5 seconds that cannot be disabled. It can be "minimized," but IF you use a transmitter (which must have line of sight to the Descent), it's crazy but the beeps continue the entire dive. The Perdix is larger and easier to find what information you seek, and unless you dive often enough to remember all the menus, the Descent fails in comparison on this too. The Garmin is a phenomenal fitness watch, but it fails as a smart watch. You can't read your mail, surf the internet or remotely answer your phone (you can, however, read your text messages but you can't reply by texting). All in all, Shearwater wins, hands down as a dive computer. However, as a fitness watch; Garmin blows Shearwater away. Yet, I wouldn't wear my Shearwater out to dinner. (lol). I do get lots of comments on my Descent due to the changable watch faces but for diving, Shearwater takes the cake.

 

[L13]

The Descent has an annoying feature, a BEEP every 5 seconds that cannot be disabled. It can be "minimized," but IF you use a transmitter (which must have line of sight to the Descent), it's crazy but the beeps continue the entire dive.

Most people can't hear the beep, especially if you set the power on the transmitter to less than maximum. The line of sight requirement is no worse (actually a little better) than the Shearwaters. The Garmin is a great fitness watch, a great dive computer, and a good smart watch(as good as the best if you aren't an Apple person).

As a dive computer, it has two advantages over the Shearwaters: GPS, and AI range. In all other regards, the Perdix is a superior dive computer. Surprisingly, the Teric is the most readable dive computer I have seen yet for old eyes. But otherwise it is inferior to the Perdix as a dive computer, but just a little better than the Garmin.

In the end, it is a trade off that each person has to do themselves. I am happy with my choice to buy the Garmin, as are many others. But for those that can hear the beep or weight the other advantages of shearwater more in their tradeoffs, the shearwaters would be better.

 

[Thrutch]

I have the Mk2 and a Perdix AI. I dive the Descent on my left because I prefer its compass and the Perdix on my right because I use the AI (sidemount) and love all the info. I prefer Garmin's logging app to Shearwater's, mostly because of the GPS entry and exit points saved and included on a map with each dive. I love Shearwater's app for the more technical side of things. They're set to the same GF and are perfectly in step. I like the displays on both for different reasons and different info. The Garmin takes a while to learn and set up, but it was my first tech computer, and I've really gotten to know it. I've used it for trail running, but having my $1000 dive computer out and about makes me anxious. I love it for warm water single tank vacation diving. The biggest difference I've found is that the Garmin reads a couple degrees colder, so I use that number when I'm exaggerating about how frigid the water is.