Raymarine down vision tranducer fitting

[Ian MacAulay]

Evening

I have had a downvue system in a box for a while and been a little worried about fitting and drilling my boat.

firstly where is the best location to fit my transducer on a twin engine set up, and also what's best way to fit to hull as I don't fancy screwing it on?



thanks

ian

 

[jimmy_the_builder]

I guess it depends on your specific transducer, I've got the CPT110 downview transducer which was bolted directly through the hull; there isn't really any other way of fitting it.

 

[Ian MacAulay]

I think its a CPT 100

thanks

Ian

 

[jimmy_the_builder]

I don't think you'll be able to fit it without screwing it to the transom.

 

[5teve]

Have a search via Google about using transom and hull mounted transducers as shoot through / thru hull transducers, apparently they work well...

Steve

 

[Murv]

I fit them in the bilge bedded down on a thick layer of CT1 (practically any sealant will work.) Has to be done very carefully though, it's absolutely critical to ensure that you don't trap any air bubbles between the transducer and the hull.
I put a thick, continuous layer on the transducer itself, then carefully press it down from one end to the other to squeeze out any air.
A lot of people do it with an oil reservoir (have a google) but I much prefer just bedding it down on the sealant.
On the last boat, I fitted it next to the engine (small boat with outdrive,) on the current twin shaft boat it's about 2/3 forward, in front of the batteries. Theory being that if creeping along in very shallow water, it might just buy me enough time to hit neutral before walloping something with the props!

Few things to be aware of, 1) you don't get accurate temperature other than when the engines are cold. 2) If you do use CT1 it's extremely difficult to remove it again at a later date.

The other problem is that there may be a loss of sensitivity in doing it this way. I'd always assumed there was, but having now passed over some underwater obstructions with a transom mounted humminbird DV system, there is no appreciable difference between that and the raymarine unit stuck down in the hull.
You may also find some interference at the top of the display, but that's easily tuned out by having a play with the gain and sensitivity settings if so.

The reason I like CT1 is that it isn't fussy if there is diesel, oil or water in the bilge, it will stick and cure regardless.

Long story short: It works, and gives a good image of the bottom profile along with accurate depth and if you're on shafts it can't be transom mounted anyway as it has to be fitted forward of the props.

 

[boatingdave]

+1 for Murvs comments. I fited the same device. Inboard of the props and shafts otherwise the turbulence will give you erroneous readings. Works fine although I did sit mine in a little sealed resevoir of hydraulic oil and it works really well. You should have had an installation guide with the sensor?

 

[Ian MacAulay]

Mine is the cpt100 down vision transducer and in manual has no mention of inside the hull due to being sensitive and 3D type images

Thanks

Ian

 

[boatingdave]

Mine is the cpt100 down vision transducer and in manual has no mention of inside the hull due to being sensitive and 3D type images

Thanks

Ian

Hi Ian - my memory was playing up. Mine was the P79 so different beast altogether. Had to google it to remind myself.
Cheers
Dave

 

[Murv]

According to Raymarine, it can't be done but I've fitted 3 like that now and all appear to work well.

 

[boatingdave]

According to Raymarine, it can't be done but I've fitted 3 like that now and all appear to work well.

Raymarine implied with mine that it had to be through hull. I didn't fancy taking the boat out of the water at the time so fitted it 'temporarily' but it works so well I won't be drilling another hole any time soon. Even if it is a different type.

 

[Murv]

Raymarine implied with mine that it had to be through hull. I didn't fancy taking the boat out of the water at the time so fitted it 'temporarily' but it works so well I won't be drilling another hole any time soon. Even if it is a different type.

Guy at the club did exactly the same, except it was a sonar unit and not a downvision. Didn't want to drill the boat so mounted it to shoot-through in an oil bath and is delighted with it!

 

[Ian MacAulay]

Thanks for the replies


Well maybe fitting inside may be a option for me and my down visiion unit then. perhaps i could just test it by having a pool of oil in the bilge and just place it there and see if it works before i attempt to some how fit it?


thanks


ian

 

[5teve]

People have mentioned using a bag of water and sitting the transducer on top of that to trial the area, holding the transducer in place via sandbags or whatever..

Worth a go if you can rig something up.. to check the area you are planning on has no voids in the glass, or turbulence underneath that may effect readings.

Steve