New Shearwater AI transmitter - the Swift

[ATJ]

On a per volume liter basis, this is 9.38 bar per 100 L to start and 8.37 bar/100L at the end. Assuming your volumetric consumption rate is the same, the pressure consumption rate (bar/min) -- and therefore SAC -- is only 12% higher at the start vs. the end. I think other factors must be contributing to the 50-100% higher SAC that is displayed on your computer.

Agreed.

I just did some calculations assuming an RMV of 11L/min (which is pretty close to mine) and I get the following SAC:
1.3 @280bar
1.1 @200bar
0.9 @60bar

The 1.3 is way lower than I remember seeing on my last dive when I was already at "steady state" and my Oceanic was displaying a realistic GTR/ATR.

The only explanation I have is that the Perdix SAC/GTR are based on the last 2 minutes while Oceanic ATR based on 90 seconds and something happened between 90 and 120 seconds from when I looked. Although, this is not the first time I have seen weirdly high SAC on my Perdix early in the dive when I am "steady state".

 

[broncobowsher]

I remember the GF99 being a "I need out of the water ASAP and will risk it, that is how much I am willing to risk it? GF99 is the line." As opposed to the standard GF already programmed. Hopefully never use it.
I also use it to see how much extra buffer I added while hanging out waiting for everyone else after my last stop has ended.

 

[inquis]

I remember the GF99 being a "I need out of the water ASAP and will risk it, that is how much I am willing to risk it? GF99 is the line."

That sounds more like SurfGF to me: it tells you the supersaturation if you blow off the rest of the stops. Although, you would be slightly lower than SurfGF, since that ignores off gassing during the ascent.

However, GF99 could be useful if you want to make the stops less quantized (very easy if GFLow=GFHigh, less so otherwise). You can ride GF99 up to maintain a desired pressure gradient, which should get you out sooner. A continuous leak of the soda bottle rather than loosen, tighten, loosen, tighten...

 

[Wibble]

For deeper dives I take a spare Perdix set to 95:95 in case of real grief. This shortens decompression time, but not by a huge amount.

It’s somewhat satisfying to see the SurfGF drop from 200+% at the beginning of decompression down to 80%, my GF-hi, at the end.

 

[RayfromTX]

I've never seen greater than 170% SurfGF but I usually exit at 50% after killing time in the shallows on my typical 4 hour dive.

 

[Wibble]

Last weekend SurfGF was 350% prior to ascending. (Never noticed this before as it's not a core piece of data; thought I'd have a look before starting the ascent for a change)

 

[RobPNW]

Wonder how the new transmitter compares in terms of signal quality or consistency, compared to the old style, specifically in situations where a diver decides to use a transmitter hose and and "stow" it in a place other than sticking straight out sideways.

 

[Scuba-Lad]

Wonder how the new transmitter compares in terms of signal quality or consistency, compared to the old style, specifically in situations where a diver decides to use a transmitter hose and and "stow" it in a place other than sticking straight out sideways.

I’m also wondering how the new transmitter performs. Was quite disappointed when I read through (all 16 pages) of this topic mostly arguing over sac and gtr.

Has anyone used the new swift transmitter?
Did you find it worth the extra premium over the old sw transmitter?

 

[Manatee Diver]

Has anyone used the new swift transmitter?
Did you find it worth the extra premium over the old sw transmitter?

I've been using one for a while, it works. I don't notice any real differences between it and the old ones. So if you are looking to upgrade, don't. But this is the standard transmitter unless you buy a PPS one from another company.

 

[Scuba-Lad]

I've been using one for a while, it works. I don't notice any real differences between it and the old ones. So if you are looking to upgrade, don't. But this is the standard transmitter unless you buy a PPS one from another company.

Thanks for the reply. Where I’m living the dive shop still sells the old grey transmitter, as well as the new swift. The price difference is about 50usd as they offer a small amount of discount on the swift. I also found someone locally selling a 2nd hand yellow sw transmitter for around 100 usd less than the new (old style) transmitter. It’s about 2 years old now but only has a handfull of dives on it and is being sold with other kit like a perdix and bcd etc. I already own a teric

I have a dilemma

New swift
Or
Old style (but new) sw transmitter - 50 usd saving
Or
2nd hand yellow sw trans - 150 usd saving (over the swift)