Shearwater Tern and Tern TX

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I have a Perdix and a Garmin Descent G1 Solar. The Garmin has full tech mode with multi-gases, GPS, heart rate, blood oxygen level, digital compass, solar charging and all the normal Garmin apps like walking, running, tides, weather etc. Battery life is pretty good, just need to charge every few days when doing multiple dives. Its only downside for me is it is black and white rather than colour. It is almost identical in NDT to the Perdix. I love it. And it is cheaper than the Tern.
 
How does the compass work on the Tern TX? Is it only visible on a separate screen, or is there a floating compass indicator?
 
Why would a scuba diver care about having GPS on a dive computer? GPS doesn't work underwater, so it's completely useless for navigating during the dive. Boats typically have their own nav system which is better than anything mounted on someone's wrist. Is the point to to have the GPS coordinates at the surface when you started and ended the dive? You could just write them down once for each site. If you dive the site again, they will be the same... I specifically would NOT want the additional battery drain associated to the dive computer operating a useless GPS antenna. A much more useful feature for a dive computer, IMHO, is good dive planning software, so e.g. if you've already done two deep dives, you can plan a third NDL dive using the computer's data, the precise gases and profile you dove, and a reasonable decompression model such as Buhlmann ZHL-16C GF.
 
Why would a scuba diver care about having GPS on a dive computer? GPS doesn't work underwater, so it's completely useless for navigating during the dive. Boats typically have their own nav system which is better than anything mounted on someone's wrist. Is the point to to have the GPS coordinates at the surface when you started and ended the dive? You could just write them down once for each site. If you dive the site again, they will be the same... I specifically would NOT want the additional battery drain associated to the dive computer operating a useless GPS antenna. A much more useful feature for a dive computer, IMHO, is good dive planning software, so e.g. if you've already done two deep dives, you can plan a third NDL dive using the computer's data, the precise gases and profile you dove, and a reasonable decompression model such as Buhlmann ZHL-16C GF.

Some people do shore dives. They get to different dive sites from the same shore entry.

Some of those people want GPS on their dive computer, so they can swim or scooter on the surface to the dive site they want, and then descend.

I'm pretty sure everybody making a GPS-enabled dive computer is smart enough to make their dive computer turn the GPS off once it's underwater, so there is no battery drain from the GPS during the dive.
 
Some people do shore dives. They get to different dive sites from the same shore entry.

Some of those people want GPS on their dive computer, so they can swim or scooter on the surface to the dive site they want, and then descend.

I'm pretty sure everybody making a GPS-enabled dive computer is smart enough to make their dive computer turn the GPS off once it's underwater, so there is no battery drain from the GPS during the dive.


I do lots of shore dives too -- exploration from shore is my favorite kind of diving -- but I don't like to spend a lot of time on the surface if at all possible. There is one beach near where I live without a lot of boat traffic, where folks without scooters on single tank OC often swim out 400m or so before starting their descent in order to extend their bottom time. Folks with scooters descend sooner because they can get there in 5 minutes, so why not do it the more pleasant way. The ppl that choose the surface swim option don't need GPS to find where they're going.

In any case, I'd just make a navigation plan, starting from the shore entry point, using distances and compass headings, and then the plan can be followed either on the surface or underwater and you can choose to descend at any time.
 
Why would a scuba diver care about having GPS on a dive computer? GPS doesn't work underwater, so it's completely useless for navigating during the dive. Boats typically have their own nav system which is better than anything mounted on someone's wrist. Is the point to to have the GPS coordinates at the surface when you started and ended the dive? You could just write them down once for each site. If you dive the site again, they will be the same... I specifically would NOT want the additional battery drain associated to the dive computer operating a useless GPS antenna. A much more useful feature for a dive computer, IMHO, is good dive planning software, so e.g. if you've already done two deep dives, you can plan a third NDL dive using the computer's data, the precise gases and profile you dove, and a reasonable decompression model such as Buhlmann ZHL-16C GF.

I only want it, to upset bad dive ops.

Pretending to write coordinates on a napkin isn't cutting it anymore.
 

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