I have my trolling motor fish finder, a Lowrance HDS 7 Gen 2 touch sitting in the factory U-shaped plastic bracket mounted to front floor of my aluminum boat. Going to have an aluminum "box" frabricated that I will then screw down to the floor and permenantly flush mount the HDS to the top of it. All the wires will then be hidden and the box will be painted to match the boat giving the unit a built in look. The question: will flush mounting the HDS to a metal surface cause interference with the GPS signal? The box will be constructed so the unit is sitting at the same angle just like it was in the bracket. Anybody have any expierence with this? Thanks in advance.