Raymarine L470 instruction manual Mounting the Transom-Mount Transducer, Installation

measured from the bottom of the transom.

•If considering the Sidelooker option, look for a mounting location where the Sidelooker array will not be blocked by the engine housing or other mounted hardware.

•If the boat will be carried on a trailer, be sure the transducer will not hit any rollers, bunks or fittings on the trailer.

Mounting the Transom-Mount Transducer

1.On a boat with a fiberglass hull, the leading edge of the transducer should extend 1/8" (3.2 mm) to 1/4" (6 mm) below the bottom edge of the hull. See Fig. 2-5. On an aluminum hull, the transducer should extend a bit more – 1/4" (6 mm) to 3/8" (9 mm). If the boat will be operated at high speeds, the transducer may be mounted closer to the centerline of the hull.

2.The lower surface of the transducer should tilt down toward the rear at a slight angle (2° to 5°). The mounting bracket includes a wedge. Depending on the angle of the transom on your boat, you may need this wedge to get the correct angle for the bottom of the transducer.

3.Looking at the rear of the boat, be sure the bracket is vertical (perpendicular to the water line).

4.Hold the bracket (and the wedge, if used) against the transom and trace the positions of the screw slots.

5.Remove the bracket. See Fig. 2-6. The screws in the outer slots should be placed about 1/4" (6 mm) up from the bottom of each slot. The screw in the center slot should be placed 1/4” (6 mm) down from the top. (This will allow you to adjust the bracket up or down a bit.) Drill pilot holes 3/4" (19.1 mm) deep. Use a 9/64" (3.6 mm) drill bit. To prevent drilling too deeply, wrap masking tape around the drill bit about 7/8" (22 mm) from the tip. Drill in only as far as the tape marker.

If you are attaching the bracket to a fiberglass hull, you can minimize any surface cracking of the gel coat. Before drilling each pilot hole, drill a shallow hole (chamfer) at each location about 1/16" (1.5 mm) deep. Use a 1/4" (6 mm) drill bit.

6.Attach the bracket to the hull using the panhead screws with flat washers. Before you tighten the screws, apply a good-quality marine sealant to the pilot holes. This will protect the hull from water penetra- tion. Do not tighten the screws completely yet.

Installation 9