Drilling holes in the hull

To install a thru-hull transducer, you must drill 3 holes in the vessel’s hull. Use the supplied mounting template to mark the hole locations.

  1. MountingDrilling holesDrilling holesEnsure that you are using the correct transducer for your chosen mounting location (i.e.: port / starboard, 0°, 12°, or 20° tilted element transducer).
  2. Using self-adhesive tape, attach the supplied mounting template to your chosen mounting location, ensuring that:
    1. the ‘Bow’ arrow on the template is pointed towards the vessel’s bow.
    2. the mounting template is parallel to the centerline of the vessel.
    3. the template is flat and not creased.
  3. Pierce the template at each hole center and mark the hole locations on the hull using a pencil or marker.
  4. Remove the template from the hull.
  5. Drill a pilot hole for the transducer stem hole.
  6. (1) Drill a hole suitable for the 68 mm (2 43/64 in) boss on the top of the external isolator plate. The boss on the external isolator plate must sit inside the hull.
    Note

    (1) It is recommended that you cut holes that are the same size as the stated values and then, if necessary, carefully file the hole to allow parts to be fitted correctly.

    If a hole cutter / drill bit of the specified size(s) is not available, use a slightly smaller size and then carefully file the hole to the correct size. Alternatively, for larger holes, you could use a jigsaw / router to cut the hole. Then carefully file the edge to create a hole of the required size.

  7. Using a half-round file and / or sandpaper, ensure that there are no rough edges or burrs around the transducer stem hole.
  8. Drill the two 15 mm (19/32 in) holes for the anti-rotation bolts.