My Detailed Initial In-Water Impressions of Garmin Mk3i

[chrisjur]

I’ve never actually seen it myself, but I believe there are two levels of that alert. A Low Warning and a Critical Alert. This is true with all computers that are compatible with the PPS and Swift transmitters. The transmitter itself only sends three levels. This is imbedded in the data string sent. While Shearwater did develop their own transmitter, they also wanted to maintain compatibility, so I really don’t see that they had an option here as the data fields available would not allow real time percentages.

Some computers do allow you to check the transmitter battery level on demand. Others, like Shearwater include this information in the dive log.

According to the docs, in the same area where you would see “No Comms” (I think many have experienced this from time to time), you would see an alert that says “BATT. LOW”. This indicates that you have <20 hours of battery life left on the transmitter.

I also have never experienced this. I had about 50 dives on it before I changed the battery just as part of regular maintenance. My impression is that these transmitter batteries last very, very long.

 

[chrisjur]

I understand the concerns about the a potential situation where the Garmin transmitter coveys tank pressure topside using ANT, but there’s some sort of failure that stops it from transmitting via Subwave when you hit the water. But the reality is that the risk is low.

Has this ever happened? Possibly, but I’ve only heard “some guy once said” stories here on Scubaboard. And if it did, you would be aware of this quickly and have the ability to ascend.

Of course, most folks continue to carry a SPG in addition to AI, so that would relieve any concerns of single point of failure. And the likelihood of this type of failure, I’d guess, would be similar to the likelihood of any AI transmitter failing when you hit the water. So while the technical nature of the problem might be unique to Garmin, the risk is generic.

 

[Jai Bar]

I understand the concerns about the a potential situation where the Garmin transmitter coveys tank pressure topside using ANT, but there’s some sort of failure that stops it from transmitting via Subwave when you hit the water. But the reality is that the risk is low.

Has this ever happened? Possibly, but I’ve only heard “some guy once said” stories here on Scubaboard. And if it did, you would be aware of this quickly and have the ability to ascend.

Of course, most folks continue to carry a SPG in addition to AI, so that would relieve any concerns of single point of failure. And the likelihood of this type of failure, I’d guess, would be similar to the likelihood of any AI transmitter failing when you hit the water. So while the technical nature of the problem might be unique to Garmin, the risk is generic.

Yes, it can happen that the acoustic transmitter malfunctions. And sure, it is not the end of the world if one notices it on beginning of dive and/or has spg.


Would that happen to me when diving in the backyard back home, I wouldn't care so much. But in the middle of safari to Galapago, discover it once we have jumped in the water into the current?? Again, no biggie, not the end of the world- but definitely would piss me off if I had to abort such a precious dive because of such malfunction.

I would assume most divers prefer to know on the boat before the dive if something malfunctions.