Question about using an Airmar P79 Smart Sensor with the Garmin 4208 - The Hull Truth

LoveTheSea · 09-07-2010, 10:30 AM

Do you know what I will see on my Garmin 4208 when I have the Airmar P79 Smart Sensor connected to my NMEA 2000 network? This is in addition to the GSD22 sounder module and Airmar 260 1KW transducer.

I am trying to get shallow water soundings and want more than just a depth reading.

Thank you,

Ben

yachtjim · 09-07-2010, 07:03 PM

Thats a good question. I don't have the answer. As far as I know the "depth" data box will default to the gsd22. I don't think you can override that and use a N2K sensor instead. This is a good question for Garmin 800-800-1020.

We have a boat we outfitted last year that has a dedicated GMI10 and N2K P79 for shallow water depth.

yachtjim · 09-07-2010, 07:03 PM

Thats a good question. I don't have the answer. As far as I know the "depth" data box will default to the gsd22. I don't think you can override that and use a N2K sensor instead. This is a good question for Garmin 800-800-1020.

We have a boat we outfitted last year that has a dedicated GMI10 and N2K P79 for shallow water depth.

LoveTheSea · 09-07-2010, 07:59 PM

Garmin did not know the answer either. They said they would call me back.

It does look like the N2K sensor will only display on my GMI10.

SaltyG · 09-18-2010, 09:51 PM

I have the GSD22 and P79 N2K transducer. Garmin will see both and you can pick one or the other or leave them in Auto mode. If you turn on GSD, then that will be the depth in the data box. If you turn off GSD, then P79 will show up in data box.

LoveTheSea · 09-19-2010, 07:05 AM

SaltyG, Are you seeing depth contour on a scrolling sonar screen? Is it slow, fast or ultrascroll? Or are you only seeing depth as a number display? I want to know if I can see fish or obstructions in shallow water with the P79 N2K. Is your 235 khz?

SaltyG · 09-19-2010, 08:59 AM

No, only the GSD22 and the transducer hooked to that, will work as a fish finder (sonar screen). The GSD box is the device that creates the scrolling images, etc, so that is the only sonar you can have. The P79 N2K is a 235 khz, so it can run at the same time and it provides depth only to the data boxes and GMI10 units. I use it just for shallow depth readings. My GSD with the big transducer cuts out at about 6 feet (too powerful). The P79 reads down to about 2 feet before it cuts out. So, it will give you depth only. Now, there is another solution...there are 2 other potential solutions if you want to use the GSD for Sonar at shallow depths. (1) go manual and turn gain all the way down. (2) Airmar makes an A/B transducer switch that would allow you to switch to a different transducer, but this gets pretty expensive and I have not experience on how well this works...but it would allow you to have 2 transducers to one GSD22. Hope this helps.