Transducer Question

JTURNER · 13 May 2019, 14:04

Hi All,

In the recent full refit I had a new Garmin Echomap Plus 95sv installed. This was paired with a Garmin P79 InHull transducer
The transducer is not working. It is showing depth for the first few metres, but it shows no detail at all on the fishfinder - absolutley nothing - just some colour/lights at the surface. The depth soon disappears as one picks up speed and then it stops working altogether.

I have been told that the issue is the hull and its penetrability, but this sounds a little unusual to me. Why make an InHull transducer that cannot penetrate through a GRP Hull?

I have been told that the best solution is an externally mounted GT30TH. This is a Thru-Hull transducer and as such it protrudes under the boat. It is proposed to mount this on the V at the Transom.

Firstly, It seams to me that the guy who did the install needs to address why the current install is not working at all. Does this sounds feasible? or are issues like this common place and I should just bite the bullet and pay the extra and look to pay for a new transducer?

Secondly if I go for the GT30-TH (which has advantages with Clear-Vu and Side-Vu capability) and it is mounted on the V - will this cause water to deflected away from the prop - potentially impacting on power? and if the boat is beached (purposely when Island hoping or to just dry out on a mooring) will this damage the sensor or its fitting? I dislike the idea of any more holes below the water line than one needs! Do any of you have experience of this? Have you used a Thru-Hull on a RIB? Have you put it on the V or elsewhere (boat is dry stacked so) I need to be mindful of positioning for when it is being moved in the yard at SDS or when its on my trailer in the summer.

Should I just forget about thru-hull and go back to putting a transom mounted one on (removed the last one to go in-hull to avoid clutter on the transom and little feet using it to hoist themselves back into the boat by standing on it).

I appreciate all your input and guidance.

Thanks

J

Nos4r2 · 13 May 2019, 22:28

Fixed for you

matata · 14 May 2019, 04:15

we have exactly the same as yours...95sv and p79...we only wanted depth but we are very impressed how reliable and stable the depth is...even max chat and rough weather...we don't use side view etc though,just depth.

JTURNER · 14 May 2019, 09:00

Quote:

Originally Posted by matata

we have exactly the same as yours...95sv and p79...we only wanted depth but we are very impressed how reliable and stable the depth is...even max chat and rough weather...we don't use side view etc though,just depth.

Thanks Matata - out of interest - what boat do you have? I find it improbably that they cannot get the existing P79 to work with my Humber hull. Thanks J

matata · 16 May 2019, 16:50

Mine is a Delta 5.5....glass/polyester hull....I would have thought the humber was the same. To give you an idea of how well it worked we simply flooded the bilge as we were going along and placed the transducer in the flooded bilge and it worked perfectly!!!

GuyC · 17 May 2019, 06:05

I've attached the installation guide which has some do's and don'ts about fitting it.

It might become obvious about which step in the process has gone awry.

Pikey Dave · 17 May 2019, 14:02

I’ve had in hull transducers in the last 2 boats with great results. They need to be bonded to an area free from air pockets/wood/voids etc. I.e. Solid GRP. The area needs to be a section of hull free from air/water disturbance caused by chimes/strakes, it should have a smooth flow of water over it at all speeds for best results. Does yours work when the boat is at rest? If not, it sounds like a placement/bonding issue. If you dangle the transducer over the side into the water, does it work?