In-hull transducer

[Heino]

On my boat there's a box for an in-hill transducer. The boat was bought with no transducer in the box, so the navy must have removed it when the boat was decommissioned.
I now want to install a fishfinder GPS unit and consider the Garmin echoMAP 75dv.
The transducer it comes with is suppose to go on the transom. The dealer said it might work if I place the transducer in the box and fill it with glycol.
The objective it to have a CHIRP sounder and I.m not sure if this will work as an in-hill transducer.
Comments please. Is there a better sounder for this application.

[gtflash]

I used a north star sounder for depth only by silkaflex ing it to inside of hull. Worked perfectly for years but it was just depth reading

[M.Thornton]

We used marine sealant to bond a standard Raymarine chirp transducer to shoot through the hull last year.It worked perfectly

[BogMonster]

Mine originally had a proper fitting and all the messing around filling with glycol etc but the fitting was stuck on wrong when the boat was built and the sounder didn't give a reading half the time as it was pointing out to the side.

I got another fitting, but there wasn't space to stick it onto the hull as I couldn't get the old one off. Somebody on here suggested I just put it on with silicone sealant, which I did, and that was about four years ago now. It worked better than the original ever did, and I haven't had to touch it again.

I don't know if a CHIRP sounder is the same technology, but if you just use ordinary silicone rather than sikaflex, you should be able to get it off again fairly easily if it doesn't work.

[Pikey Dave]

I have a Lowrance HDS 9 gen 3 with an M260 in hull transducer. Chirp works perfectly.

[Last Tango]

Old Lowrance lcx16 with transom skimmer transducer bonded inside the hull.
Clear bottom trace to about 30 meters at 25kn+. (Much, much deeper at slow speed.)
The only aspect of the performance likely to be effected is absolute range and if it's that deep it probably doesn't matter anyway

[GuyC]

Garmin have a section on transducers including through hull ones. They are quite expensive compared with the transom mounted ones. I think it also depends on how you use the boat. The transom mounted ones can be a bit vulnerable if you do lots of launching.

http://www8.garmin.com/transducers/d...guide-2015.pdf

[Pikey Dave]

Originally Posted by GuyC

Garmin have a section on transducers including through hull ones. They are quite expensive compared with the transom mounted ones. I think it also depends on how you use the boat. The transom mounted ones can be a bit vulnerable if you do lots of launching.

http://www8.garmin.com/transducers/d...guide-2015.pdf

Most, if not all transducers are made by Airmar & rebadged by the different manufacturers who have their bespoke plugs fitted to the cables. That's why all the different manufacturers offer more or less the same transducers.

[Chris]

If its just for depth reading then shoot through hull works ok, but you will get more detail when its transom mounted. The ultimate solution to this is a proper through hull transducer mounted externally.

[DavidMarten]

I've been using a Garmin plotter with a transom mount transducer fixed with silicon internally on the big boat for the last two years, works fine.

[GuyC]

Originally Posted by Chris

The ultimate solution to this is a proper through hull transducer mounted externally.

Interestingly Garmin suggest two through hull transducers if you have a large deadrise angle so the hull doesn't create a shadow. I suspect it again depends on whether you are using the side sonar function or not.

[jonp]

I've cut holes through my boats hulls before trying to get the most out of transducers and have found in most cases the simple external bracket works fine.

I would not recommend the 1kw transducers unless you like telling everyone you have a big one that cost more I fish for deep water fish using big electric reels with 1500m of line and 5kg sinkers, mostly in water 300-1000m deep. I ran both lowrances standard 200/50htz and airmars tm260 and found the much cheaper Lowrance sounder was consistently better.

I tried talking two of my mates from buying the tm260, one for Lowrance and the other for furono. Both regretted it and like me have since sold them on ebay.

What depth are you wanting to sound as I can read bottom even up to 300m at 40kmh on 200htz and much deeper on 50htz at lower speeds (from a $200 transducer) external bracket mount.

Jon

[sameh]

Originally Posted by Last Tango

Old Lowrance lcx16 with transom skimmer transducer bonded inside the hull.
Clear bottom trace to about 30 meters at 25kn+. (Much, much deeper at slow speed.)
The only aspect of the performance likely to be effected is absolute range and if it's that deep it probably doesn't matter anyway

Do you have pictures for fitting?

[sameh]

Originally Posted by jonp

I've cut holes through my boats hulls before trying to get the most out of transducers and have found in most cases the simple external bracket works fine.

I would not recommend the 1kw transducers unless you like telling everyone you have a big one that cost more I fish for deep water fish using big electric reels with 1500m of line and 5kg sinkers, mostly in water 300-1000m deep. I ran both lowrances standard 200/50htz and airmars tm260 and found the much cheaper Lowrance sounder was consistently better.

I tried talking two of my mates from buying the tm260, one for Lowrance and the other for furono. Both regretted it and like me have since sold them on ebay.

What depth are you wanting to sound as I can read bottom even up to 300m at 40kmh on 200htz and much deeper on 50htz at lower speeds (from a $200 transducer) external bracket mount.

Jon

What tansducer is it? Chirp?

[jonp]

Originally Posted by sameh

What tansducer is it? Chirp?

Non chirp HST-DFSBL 50/200KHz T/M Deep Water Transducer

[sameh]

Originally Posted by jonp

Non chirp HST-DFSBL 50/200KHz T/M Deep Water Transducer

Up to 900 m specs! Impressive

[Orwell boy]

You can easily check ultrasonic sensors function by holding it in place on the inside of the hull with some acoustic couplant (ky jelly is fine ) ,this will let you see what results will be like and you can find the best spot and silicone or araldite later ,

[jonp]

Originally Posted by sameh

Up to 900 m specs! Impressive

I havent really experimented to see what depths I can get from mine as I normally set the max depth to around 80m while in very deep water 2000m +. I set it at that depth so Im only searching the water column the game fish are likely to be in.

This is from my first hds, the lines down the screen are from where I start my engine to drive back up the drift. Note it still holding bottom at 40kmh from just an external mount transducer and all depths are in metres..





This is about as far as I bottom fish and to do this I use an ellectric reel with 10 lb sinkers.



This shows soft plastic lures dropping down and fish rising to meet the lure (still the old hds)



This is from the new hds gen 3, still early days for me but so far loving it, its great for locating new dive and fishing reef.





By the way you need a second transducer for sidescan, which I fixed directly under my hull without the need to use the brackets.