Humminbird 859 transducer position

I just bought an 859 and put the transducer a 1/4 from the bottom of the boat per the directions and about 15" to the right of the motor. The problem is my 1998 Javelin has a step hull and creates a vortex, if you will, at the bottom of the boat. After I get up to 4 or 5 mph the sonar screens wash out and shows nothing. It's fine at idle and just a little above though. The step is only 2 inches tall at best and the mount itself is around 2 1/8". Any ideas on how to mount this to make it work properly? Thanks.

The 15" statement in the installation manual is for outdrive boats that have the prop forward of the transom ...

The only restriction for outboard boats is not to mount the xducer directly in front of the outboard ...which could cause bubbles getting to the outboard that could cause cavitation or loss of water pickup for the water pump ...

Can you post pix of your transom ... ??

Rickie

You could always epoxy the transducer inside-the-hull. This is normally the best location for high-speed depth readings on a fiberglass boat.
Which unit do you have, the 859ci HD (2D sonar) or the 859ci HD DI model?

Greg, I have the 859 HD DI.

Our DI transducers can be epoxied inside-the-hull.

Here is a pic of the position.
http://i296.photobucket.com/albums/m...ps8bs0wqpm.jpg

The blue part of your transom is completely out of the water on plane ...the boat rides on the lowest part "pad" of the underside hull ...

If you want DI at high speed ...:

You will either need to mount the xducer on the lower step to get the xducer in the water at high speed ...or mount the DI xducer as a shoot thru in the bilge to "shoot thru" that "pad" area of the underside hull ...

Rickie

The blue part of your transom is completely out of the water on plane ...the boat rides on the lowest part "pad" of the underside hull ...

If you want DI at high speed ...:

You will either need to mount the xducer on the lower step to get the xducer in the water at high speed ...or mount the DI xducer as a shoot thru in the bilge to "shoot thru" that "pad" area of the underside hull ...

If you just want DI at idle ... You can move the xducer lower to the left on that same blue part and get it farther down in the water at idle ...

Rickie