Depth Sounders/Fish Finders

[Dockhead]

One of the unplanned problems which occurred during my recent (and still ongoing) refit was someone stepped on my depth sounder (an Airmar DT800) and broke it, which weirdly took down my entire network. I got the network back up by isolating each device one by one, but I don't have depth at the moment.

Another DT800 is logical, but one of my plotters (B&G Z8 and B&G T8, both first generation) has a built-in sounder, which may or may not require a Sonar Hub to work with a fishfinder sounder.

I would actually love to have more detail about the bottom for anchoring in remote places, so I wonder if instead of the DT800 there is some other more powerful sounder which could be used with the plotters' built in fishing functions which show the bottom structure graphically?

It's maddeningly difficult to parse information about this from the Navico websites -- maybe some one, perhaps a fisherman, can give me a steer on this?

[mickt243]

If it says it has built in sonar, you don’t need a sonar hub.....

However, many models are often covered by the same manual, so your first step is to have a look at the back of each unit to see if there is a connection for the sonar transducer.

Once you confirm you do in fact have a built in sonar, the number of pins in the connection may hint as to its capabilities. Later models tend to have more features. Then we need to figure out what transducers will work for you - some will only give depth, others give varying 1,2 or 3 dimensional representation of what’s below...

[Dockhead]

Originally Posted by mickt243

If it says it has built in sonar, you don’t need a sonar hub.....

However, many models are often covered by the same manual, so your first step is to have a look at the back of each unit to see if there is a connection for the sonar transducer.

Once you confirm you do in fact have a built in sonar, the number of pins in the connection may hint as to its capabilities. Later models tend to have more features. Then we need to figure out what transducers will work for you - some will only give depth, others give varying 1,2 or 3 dimensional representation of what’s below...

This is what the manual says:

"
Internal echosounder
The Zeus Touch 7 and Zeus Touch 8 have an Internal Broadband Echosounder. Navico transducers fitted with the 7 pin blue connector can be plugged directly into the correspondingblue socket adjacent to the power connector."

[a64pilot]

My Zeus has the internal sounder. All you need is an xducer to plug into it.
I installed one that shoots thru the hull, and it works excellently, you can find wrecks to Dive on with it etc, tell bottom types and yes find fish, or at least things in the water column.
Interestingly my Raymarine I 60 depth with its xducer mounted in the hull will only work to a few hundred ft, but the Zeus will go to over 1500, and maybe deeper if I changed the frequency, I think it’s dual frequency, but am not certain.
I wanted a second depth gauge as I’m often in shallow water.
It is a very good bottom machine
Nearly certain that it puts depth on the Network too.

[Dockhead]

Originally Posted by a64pilot

My Zeus has the internal sounder. All you need is an xducer to plug into it.
I installed one that shoots thru the hull, and it works excellently, you can find wrecks to Dive on with it etc, tell bottom types and yes find fish, or at least things in the water column.
Interestingly my Raymarine I 60 depth with its xducer mounted in the hull will only work to a few hundred ft, but the Zeus will go to over 1500, and maybe deeper if I changed the frequency, I think it’s dual frequency, but am not certain.
I wanted a second depth gauge as I’m often in shallow water.
It is a very good bottom machine
Nearly certain that it puts depth on the Network too.

OK, thanks. WHICH transducers will work with it? Do you know? Would you recommend one which would mount in the standard I believe 2" Airmar hole? I don't think I can shoot through the hull, as mine is cored and more than 4" thick except in specific areas designed for through hulls.

[mickt243]

Any Navico transducer with the 7 pin plug will work.

So will many airmar transducers (may or may not need an adaptor)


I ran my simrad (also navico) go7 through a very old airmar (factory fit p319 I think)and it worked quite well, but eventually I fitted the navico totalscan transducer so I could get structure scan and side scan.... for what you seem to be desiring, an airmar p19, p7 or p8 may well be just the ticket - assuming you can get one with the right plug (I bastardised a navico 9 pin extension cable to connect mine)

Or any nearby boat/fishing shop should be able to get you a transom mount navico w 7pin plug.... or even eBay...

[ranger58sb]

You might get decent info about transducer match-up direct from Airmar; they were helpful once (by phone) when I had a question about a potential replacement transducer...

FWIW, when we were installing redundant depth instruments (DST sounder and DST fishfinder) the installers recommended devices with different frequencies to eliminate interference. So our FF uses 50/200 Hz and the other sounder uses 235 Hz. Can't tell whether that's been useful or not...

-Chris

[a64pilot]

This is the one I used
https://www.iboats.com/shop/lowrance...0aAu_VEALw_wcB
There are even adapter cables available to adapt 9 to 7 pin transducers, as you know it’s only the plug that makes the transducer fit one model sounder or the other.
https://www.lowrance.com/lowrance/ty...AaAk7aEALw_wcB
https://www.simrad-yachting.com/simr...QaAkOkEALw_wcB
You can fit a shoot thru, what is done is an about 6” section of the outer skin and core are removed and sealed, this gives you direct access to the outer skin. You cannot shoot thru the core.
I’m certain that there are ones that can replace your existing transducer, and almost certain that if you want to use the existing one, all you need is an adapter cable, or change the end.
I did it to have two sources of depth, plus of course it puts depth on the network, at the time I had old standalone ST60 depth that was not NMEA capable.

[CFS Klopas]

Combination chart plotters/fishfinders are generally cheaper than equivalent stand alone chart plotters in the US. I assume its because fisherman are cheaper than yachties.

[belizesailor]

I got one of these as a promotional freebie from Navionics, but still only $150 on Amazon.

Installed in starboard hull (ships sounder is in port hull). So now I can see depth under both hulls (thats a realistic issue on a cat!)...and its totally separate from my main system so gives me full redundancy too. Its also pretty cool...get fish finder functionality via WiFi on tablet or phone.

https://www.amazon.com/Vexilar-SP200...ds=Sonar+phone

[KeelMe]

Originally Posted by Dockhead

OK, thanks. WHICH transducers will work with it? Do you know? Would you recommend one which would mount in the standard I believe 2" Airmar hole? I don't think I can shoot through the hull, as mine is cored and more than 4" thick except in specific areas designed for through hulls.

Any 600W 50/200 kHz transducer will work with it. It will require the blue 7-Pin Plug. I would recommend a B117-DT-BL unless your DT800 was a tilted element. If it was tilted I would recommend a B60-20-BL(20 degree) or B60-12-BL(12 degree). These are both bronze transducers and you can step on them all you want.

Also if you find a good deal on an Airmar 600W 50/200 kHz transducer(non NMEA) you can always cut the plug off and replace it with the proper plug. If you can't find the plugs let me know, I can get one for you.

You should be able to find a plastic one for $100 or less.

Better yet, get in touch with the folks at JK Navigation, their engineers are top notch. They don't have much in the way of 50/200kHz transducers on their website yet but I know they have them.

[sailjumanji]

Originally Posted by a64pilot

You can fit a shoot thru, what is done is an about 6” section of the outer skin and core are removed and sealed, this gives you direct access to the outer skin. You cannot shoot thru the core.

What we did on our Corsair trimaran was to cut out the inner skin and core, and then fill the cut-away with epoxy. The transducer will shoot thru the epoxy and outer skin/hull easily. We affixed the transducer to the hull with silicone, which would allow it to be removed if there were problems. Worked well with no issues.

There are also some transducers specifically for shooting thru-hull. The Garmin unit on my fishing boat uses one, that the transducer mounts into a tube filled with mineral oil. It is a dual-frequency chirp transducer that does an excellent job of showing bottom. I think it is model GT-51.