Help with Garmin GPSMAP750s settings and intepreting

Guys I have a Garmin GPSMAP750S sounder combo unit, I would like to know if anyone else is using one of these and what settings you use (gain, white line, nise rejection etc etc.

I have had it for nearly 2 years now but I'm still struggling with it, mainly once I am deeper than 30m I struggle differentiate the bottom doesn't really get thicker (harder bottom) or show any significant tails on the bottom of the echo (broken ground).

I don't have a problem detected echo's off the bottom and mid water it's more so reading and understanding the bottom.

cheers in advance


JohnF's picture

Posts: 2837

Date Joined: 07/07/10

yep, I have one. The GPS

Thu, 2015-05-14 16:04

yep, I have one.

The GPS side is excellent, the sounder side is weak.

I have used it in direct comparison to my Furuno 587 on the same transducers (I have them wired up so I can swap between the two) and the Garmin sounder has much lower sensitivity and drops out about 200 m shallower than the Furuno, ON EXACTLY THE SAME TRANNY.

Surprising but true. I have tweeked the Garmin unit but no amount of adjustment will get it even close to the Furuno.

I use the Garmin sounder so I can back track to drop GPS points on the move but leave all fish finding to the Furuno.

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Boston Whaler 235 Conquest......getting the flogging it was built for.

Posts: 23

Date Joined: 08/11/09

 What settings do you run on

Thu, 2015-05-14 18:35

 What settings do you run on gpsmap

JohnF's picture

Posts: 2837

Date Joined: 07/07/10

Full auto is not much

Thu, 2015-05-14 19:38

Full auto is not much different to manually adjusting it for me so I just leave it in auto.

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Boston Whaler 235 Conquest......getting the flogging it was built for.

DTrain's picture

Posts: 486

Date Joined: 10/02/12

I've got one hooked up to a

Fri, 2015-05-15 11:55

I've got one hooked up to a TM260 transducer (1kw). I've tried fiddling with the settings, but in the end leaving it on auto was pretty much as good.

I used to have a FCV620 with the 600w transducer and I think that the Furuno was better for anything shallower than about 100 meters. Deeper than that the 1kw on the Garmin starts to win out.

Also the GPS side is really good, but around Perth the Bluechart maps aren't as detailed as the Navionic maps.

 

Here's a pic of some fish (I think I caught a Dhufish near this spot) on what I think is flat gravelly bottom. Hope that helps.

Perfish's picture

Posts: 103

Date Joined: 15/11/11

Ditto

Fri, 2015-05-15 13:50

I have exactly the same config as JohnF (except tm vs through hull for the 1kw) and run the Garmin as a GPS and sounder in auto everything if I use it at all and typically only to add marks as we're travelling or searching.  Would suggest thinking about upgrading to a new sounder and keep the 750 as a GPS with backup sounder capability.

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Man with line in water catches fish!

You only get what you always got if you only do what you've always done!