Installing In-Hull transducer - what is my hull thickness?

[Loose Cannon]

Recently purchased an '07 280 Sundancer and I have someone installing a Garmin 740s GPS tomorrow. Just ordered an Airmar P79 In-Hull transducer and 6 to 8 pin adapter (recommended by West Marine). I called Airmar who said the transducer would be lucky to transmit through a 3/4 inch thick hull which concerns me. Anyone know how thick the hull is in the engine room where a transducer would be mounted in-hull? Any other experiences with In-Hull transducers with the 280DA would be appreciated.

 

[Mike Blake]

I have one and it works great!!.

 

[JimFromMD]

My system is installed with the Garmin in-hull ducer and it works great as well. Part number below. There's also a thread here which shows where it was mounted in a photo. I wonder if that's why some of those indented spots in the hull are there. Small patches of thinner hull for installations like this.


Here's a photo of the mount/setup.
http://clubsearay.com/showthread.php...655#post499655

1​

010-10327-00 -​

Garmin 200/50kHz, 12/45Deg, Plastic, Adj. In-Hull Mount Transducer​

 

[hottoddie]

I just installed on in my 390 this past weekend and the hull is 3/4" thick. It works fine in the slip so far up to 16ft depth anyway. I used an abrasive wheel to remove about 1/16" before using silicone to attach the mounting ring. I also know of several other boats at our yacht club with the P79 and none have had issues. As long as the hull is not cored (and I believe your is not) you should be fine.

 

[SCORPIO]

I just installed one on my 300DA with a Garmin GSD 22 'black box' sounder, works well at least at the dock since I haven't had her out yet with the new 'ducer. If you have the GSD 22 you will need that adapter cable as the black box is a 6 pin.

 

[Loose Cannon]

Well, my new Garmin 740s GPS works great; however, the Airmar P79 in-hull transducer is not working. No depth reading is displayed on the GPS. Any suggestions would be appreciated.

 

[kaz911]

Well, my new Garmin 740s GPS works great; however, the Airmar P79 in-hull transducer is not working. No depth reading is displayed on the GPS. Any suggestions would be appreciated.

It takes quite a while to find a spot for a in-hull transducer will work fine. Don't put it on the "raised" bilge parts. Follow the MANUAL for the transducer and play around with the P79 in different spots (in a plastic bag with water in it)

I have the M260 in my 310 and it works okay. But SR hull's are thick.... If you want the P79 to work anywhere in the bilge - the only option is to change to a Bayliner *G* -

but as I said.. EXPERIMENT before choosing a location. Go to 100' of water - check a few places in the bilge until you get a solid return. Then watch the solid return for a bit - then hang the P79 over the side still in the bag - and see if return looks the same. If they are quite similar you found a good place.

Even the SMALLEST bubbles in the fibreglass WILL make an in-hull transducer give up and get confused. Bilge paint will take efficiency down as well. But don't remove all the bilge paint before you have a reasonable location.

 

[hottoddie]

Well, my new Garmin 740s GPS works great; however, the Airmar P79 in-hull transducer is not working. No depth reading is displayed on the GPS. Any suggestions would be appreciated.

Does the 740s recognize the P79 in the systems list? If it does and you are not getting any depth then it was probably installed wrong or is in a poor location. I had mine out Sunday for the first time and it was fine at least up to 60ft. It's important the the install angle is correct and the cup is filled with 2.4 ounces of propolene glycol in order to work correctly.

 

[kaz911]

Does the 740s recognize the P79 in the systems list? If it does and you are not getting any depth then it was probably installed wrong or is in a poor location. I had mine out Sunday for the first time and it was fine at least up to 60ft. It's important the the install angle is correct and the cup is filled with 2.4 ounces of propolene glycol in order to work correctly.

Most P79's does not have XID (the ID that identifies the transducer to the chartplotter) - so you have to set it manually in the transducer settings.

And for filling liquid - you can use water to start out with. The propylene glycol is safer in cold climates though as it wont freeze until ?? (read the label)

 

[Loose Cannon]

I played around with the GPS settings. Changed the Sonar frequency from 200khz to 50khz and now have depth readings that seem accurate. I need to read about that setting to understand a little more; however, seems I might be in business. The 50khz is supposed to be for deeper waters according to the Garmin 740s manual. If I change it back to 200khz, no depth reading at all.

 

[mikenewhouse]

I played around with the GPS settings. Changed the Sonar frequency from 200khz to 50khz and now have depth readings that seem accurate. I need to read about that setting to understand a little more; however, seems I might be in business. The 50khz is supposed to be for deeper waters according to the Garmin 740s manual. If I change it back to 200khz, no depth reading at all.

I had the exact same issue with my 740s, don't know why 200khz does not work but 50khz works great.

 

[kaz911]

If you use inhull transducers on Sea Ray's remember they got elephant skin (Think hull's) - so you need to TEST for where the best place is for the in-hull transducer. And once you have found the best place - remember to remove the bilge paint and get down to the transparent fibreglass. Paint blocks signals as well.

50 kHz penetrates MORE than 200 kHz - so it is harder to get a good return on 200 kHz. So if you get return on 50 but not on 200 - then either it is in the wrong location - or it does not have the power to blast through your hull (and sensitivity to receive it)

I have the M260 - which is much more sensitive and much bigger (P79 is deaf in comparison) - and it works ok in 50 and 200 kHz with my Simrad NSS8 "250/500 watt" sounder. Even though the M260 is a 1 kW transducer. But I could not get a P79 to do anything for me at all. But I did not spend a lot of time with the P79 as I already had the M260.