Please help me figure out my depth finder/sonar transducer mounting out!

[Bass newb]

Okay, the Mark 5 Lowrance unit that I'm replacing has an in-hull puck glued to the hull bottom where that carpet covered skid runner supports the boat below where I'm holding the new side view transducer. I'm holding the sideview transducer where the boat water temp sensor hole has already been drilled. 

What I want is to be able to tell depth while at full speed of 50mph. It looks to my inexperienced eye like I will have to make some compromise. ..either buy a small in dash gage that will use the current in-hull transducer for depth readings at all times, or use the mark 5 for such, and then use the sv transducer at lower speeds?  If i mount that transducer  right there where I have it, how well could it work at speed? Not very good is what I assume.

 

Please school me on the smartest thing to do !

 

There does not appear to be anywhere that I can mount the transducer and have it work and also not get damaged by the trailer. 

 

Should I just mount it low and cut back the trailer runner so that it won't hit my transducer? 

Best case scenario would be to use the garmin gt40 tm for everything up to boat top speed of 50mph. Second  best would be to use the puck transducer already installed for depth and use the garmin transducer up to xxx? speed?

I really don't want to see the Lowrance mark 5 on the boat ever again. A little depth-only gage would  be fine though.

 

Please advise. 

[Wayne P.]

If you want a transducer to give you depth at speed, it has to be where the hull bottom is when the hull is on plane (surface). That is down there below the hull drain. The black part of the hull.

Where you are holding it will be out of the water when on plane and no way could it work at speed.

Where you are holding it will work at idle speed or sitting still.

Is there not a splitter cable to use the shoot-thru you have and the sv transducer where you are holding it?

A proper installation for your hull type is a shoot-thru for depth/2D sonar.

[Bass newb]

13 minutes ago, Wayne P. said:

If you want a transducer to give you depth at speed, it has to be where the hull bottom is when the hull is on plane (surface). That is down there below the hull drain. The black part of the hull.

Where you are holding it will be out of the water when on plane and no way could it work at speed.

Where you are holding it will work at idle speed or sitting still.

Is there not a splitter cable to use the shoot-thru you have and the sv transducer where you are holding it?

A proper installation for your hull type is a shoot-thru for depth/2D sonar.

I am unaware of a "split " or shoot through that you speak of.

Is it possible to use a garmin aftermarket with a Lowrance oem transducer?  That doesn't seem intuitive to me. 

Edited February 3, 2016 by Bass newb

[Wayne P.]

OHHH I thought you were replacing another Garmin.

I know there is an adapter to use a Lowrance shoot-thru with a Humminbird unit and Humminbird has a splitter cables that do what I mentioned. Typical setup for those changing from Lowrance to Humminbird Side Imaging.

There is probably a Motor Guide built-in transducer Garmin adapter, then you would have a conversion from Lowrance to Garmin. Don't know if Garmin is up to date enough with their technology to have a splitter cable for the type of installation you need. The splitter cable would disconnect the 2D crystal in the SV transducer and connect the added 2D transducer in its place. That is the way Humminbird does it. Contact a Garmin dealer and ask.

Your next best choice is use the Lowrance for on plane use and then the Garmin at idle speed. That way you can have the SV transducer where you are holding it and it would be protected from possible impact damage.

[Bass newb]

I think mounting the transducer where it needs to be mounted and then cutting away the runner on the trailer that interferes may be the way to go.

That will be nearly pain free, except for the trailer. 

 

[Bass newb]

On 2/3/2016 at 5:06 PM, Wayne P. said:

OHHH I thought you were replacing another Garmin.

I know there is an adapter to use a Lowrance shoot-thru with a Humminbird unit and Humminbird has a splitter cables that do what I mentioned. Typical setup for those changing from Lowrance to Humminbird Side Imaging.

There is probably a Motor Guide built-in transducer Garmin adapter, then you would have a conversion from Lowrance to Garmin. Don't know if Garmin is up to date enough with their technology to have a splitter cable for the type of installation you need. The splitter cable would disconnect the 2D crystal in the SV transducer and connect the added 2D transducer in its place. That is the way Humminbird does it. Contact a Garmin dealer and ask.

Your next best choice is use the Lowrance for on plane use and then the Garmin at idle speed. That way you can have the SV transducer where you are holding it and it would be protected from possible impact damage.

Thanks for the suggestion. I just moved the front winch mount back by one bolt hole (3"). That got me into this:

This performed perfectly going to the spot at 51mph, but on the cruise back, the depth gage was blinking.  Half of it is in the water stream, and the other half is behind the hull of the boat due to the angle of the rear hull.

[Wayne P.]

Good job--you are close.

ALL of the bottom of the transducer should be below the bottom of the hull that is forward of it. Lower it about another 1/8"-1/4" and check for performance.

If any of the transducer is above the hull that is forward of it, you get cavitation and sonar does not work through air.

 

[Bass newb]

On 2/7/2016 at 6:36 PM, Wayne P. said:

Good job--you are close.

ALL of the bottom of the transducer should be below the bottom of the hull that is forward of it. Lower it about another 1/8"-1/4" and check for performance.

If any of the transducer is above the hull that is forward of it, you get cavitation and sonar does not work through air.

 

Thanks. Lowered it 1/4 more and now it's perfect