fishfinder question

[niteman]

I am going to get another depthfinder for my boat with higher resolution, the one I have now is a humminbird wide portrait with 120x120 resolution. My question is, do I put the old one on the transom to find structure and the higher resolution one on the trolling motor to look at the structure with more detail. or vice versa. It makes sense to do this, but I wanted some more opinions. thanks

[whizkids]

I personally like the one with the highest resolution on the trolling motor. That is where you fish and in my opinion where you need more detail. Transom mounts can be tricky depending on the boat and at what speed you want to be able to read the structure. The transducer needs to be mounted so that it is in the water at top speed and where it will receive the least turbulance. Lowrance and probably hummingbird have tips on transducer mounting.

http://www.lowrance.com/support/installation_guide.asp

Location

1. The transducer must be placed in a location that has a smooth flow of water at all times. If the transducer is not placed in a smooth flow of water, interference will show on the sonar’s display in the form of random lines or dots whenever the boat is moving.

2. The transducer should be installed with it’s face pointing straight down, if possible.

3. Make certain the transducer's location doesn’t interfere with the trailer or hauling of the boat. Also, don’t mount it closer than approximately one foot from the engine’s lower unit. This will prevent cavitation interference with the propeller. Typically, the transducer should be mounted as deep in the water as possible. This increases the chance that it will be in the water in high speed and reduces the possibility of air bubble interference.

[kmatcek]

This is what I did.
I bought a new eagle fishfinder 320 and mounted that to the trolling motor on the front of the boat. I put the old hummingbird on the transom to narrow in on the area I wanted to fish. I really only use it for finding the river channel and holes then stop and drop the trolling motor to narrow down the area and find the brush piles.
So far it is working fine I still want to upgrade the old fishfinder one day but till then I am very pleased.
Kenny