Need some help re depthfinder

[TorronnaPwr]

Hi everyone, back to the well of wisdom for help regarding changing my current depth finder on which the numerals are fading out or disappearing altogether.

The current model is a Lowrance 3500 installed in 2002. I believe the model is discontinued and gauges are unavailable wherever I've searched for them.

Does anyone know if there is a dash gauge which would be compatible with the thru hull transducer?

If not, will I need to buy a new transducer and gauge?

Last question. If I need to buy both transducer and dash gauge can you recommend a unit compatible to a Simrad NSS evo2 MFD? I get overwhelmed with the number of choices and confused by compatibility with the MFD.

I use this only for depth, no fishfinding, forward looking, bottom scanning needed, so cost and simplicity are most important to me. The hull is cored construction.

Thx in advance for all thoughts

[Spot]

Hey TP-
I think you'd need to know the make/model of transducer, rather than the old instrument, to begin to answer this. Is it accessible on the boat, to where you could snap a cell phone or inspection scope picture?

[tkeithlu]

I suggest that you consider this route. For reasons unknown, simple fish finders are cheaper than depth-only sounders like you had. They also give you more information, such as a rough idea of the bottom, large rocks directly under you, and the trend in depth.

Second point: If the bottom of your hull is straight fiberglass with no core, as are most, then you can mount the sender in the bilge with 3M 5200 or even silicone goo. It will adequately send and receive right through it.

Therefore, there's a pretty cheap way out of your problem as in this one for $99 with transducer included:

https://www.amazon.com/Humminbird-41...%2C221&sr=8-14

[TorronnaPwr]

Thank you both for your replies

Spot - I've looked everywhere inside the hull but can't identify the transducer. I'll attach pix of the exterior hull - perhaps it's possible to know which of these thru-hulls is the transducer? - then I can narrow down the search inside.

tKeithlu -Unfortunately the hull on this power boat is cored. I had a repair of approx two square feet a few years ago and watched them use a balsa mat sandwich. I think this rules out the shoot-through-the hull transducers.

I agree it is better to have more information. I had looked at Simrad transducers, as my MFD is Simrad, and they were priced around $800Cdn. Mucho dinero lol. I was hoping to find a cheaper way.

[TrentePieds]

Tronna:

The gizmo in your second photo is the transducer. By sighting vertically up the hull at that "station" (distance from the bows), you should be able to identify some part of the superstructure that you can also identify from below decks. Vertically below that you'll find the transducer. The "give away" that you have found it, is that it will have a cable going from it to wherever your display is located.

TrentePieds

[TorronnaPwr]

Hi TP - that really helps, both for me to know my boat better and yes, to get a sight line to the interior location.

The boat is on the hard right now, so I'll go down next week and try to get an interior pic of the transducer. Thx!

[Nord Sal]

I just searched and found this manual for the Lowrance 3500 sounder.
https://usermanual.wiki/Lowrance/Low....183459863.pdf

It looks like it's a 192 kHz transducer (see page 2) so that may help you find a different display unit that is compatible with your transducer.

Since this is an older model, I suspect you can find a working 3500 display on ebay for not too much money.

[TorronnaPwr]

Thx Nord Sal, with that information I've decided to call Lowrance and ask if they have a compatible gauge.

I did check your suggestion re using ebay or other sites to find the dash gauge, but after getting excited about a listing only to find it was just a bezel, I saw on some other feeds that the actual gauges rarely are offered. Appreciate the manual link

[RaymondR]

Originally Posted by tkeithlu

I suggest that you consider this route. For reasons unknown, simple fish finders are cheaper than depth-only sounders like you had. They also give you more information, such as a rough idea of the bottom, large rocks directly under you, and the trend in depth.

Second point: If the bottom of your hull is straight fiberglass with no core, as are most, then you can mount the sender in the bilge with 3M 5200 or even silicone goo. It will adequately send and receive right through it.

Therefore, there's a pretty cheap way out of your problem as in this one for $99 with transducer included:

https://www.amazon.com/Humminbird-41...%2C221&sr=8-14

A fish finder is better to have anyway, it's a lot easier to just watch the slope of the bottom on the fish finder than remember and compare the numbers on a depth only gage and you can get a good idea of bottom conditions with a fish finder, particularly with a colour one.

[AKA-None]

First pix is that looking forward or aft?
Reason I ask is that strainer in the upper left corner is facing the wrong way. When traveling through the water the strainer can may force water into your cooling system. Eg funnel water into
Just something to think about

[Jammer]

Theoretically many sounders will work with your existing transducer. In practice it is hard to identify exactly which sounders use which frequencies and what sort of connectors and pinouts apply.


With care, it is possible to drill/cut through the hull core from the inside of the boat using a hole saw or Forester bit, and chisel, leaving the outer fiberglass layer intact, to facilitate installation of an in-hull transducer inside the hull. An alternative to consider.


On the other hand, if your boat is already on the hard for the winter, why not install a modern thru-hull transducer and depth indicator? That may be cheapest and most performant for the money.

[TrentePieds]

Torronna:

AKA is right. You should check the orientation of the intake strainer. If you do not already know why it is dangerous to have water FORCED into the raw water side of the cooling system, sing out and we'll explain!

TrentePieds