Arctic Loon is a 1991 37.5 that we purchased in mid-2005. The boat was in excellent physical condition for her 14 years but was in need of an electronics refresh. The existing GPS-based navigation system no longer functioned consistently so we chose this system as our first replacement project. After several weeks of evaluating Chartplotters, we chose a Raymarine C-80 multifunction display paired with a Raystar GPS sensor. We decided to install the display at the helm, where we would get the most use of the display capabilities. We also wanted the ability to replace our older ST-50 instruments, located on the starboard bulkhead, with ST-60s located above the chartplotter. Though it would have been easier to replace the instruments as we installed the chartplotter, we decided to tackle them as part two of the project at a later date.

The project consisted of replacing the pedestal guard mounted on the Edson pedestal with a guard capable of handling the chartplotter and instruments. Here we had a choice to make; extend the pedestal guard to the cockpit sole and drill holes for the cables in the sole or modify the existing guard and run the cables through the Edson pedestal. We could not determine if there was adequate space under the cockpit sole to run cables without having them exposed in the aft cabin so we chose the in-pedestal route.

First we separated the existing pedestal guard, loosening the set screws just below the pedestal brace and separated the short u-shaped guard from the lower guard mount. We then removed the guard mount from the pedestal. We wanted the guard to have enough room for the chartplotter, instruments, and still have a handhold at the top, we selected the angled guard with two 45 degree bends. The guard comes standard in a 58” length, but since we were using the existing lower half of the guard mounted on the pedestal we needed to trim 29 inches from each of the legs to give us the proper height.

Old pedestal guard removed

We measured the location for the Navpod cases and drilled the mounting holes according to the instructions provided. The Chartplotter was then installed in the Navpod face and the cables were run through the holes drilled in the new top half of the guard. The lower guard is welded to a flange that mounts on the pedestal tube. A hole was drilled in the flange to allow the cables to exit the guard tube. Next we matched the flange to the pedestal to mark and drill the corresponding holes in the pedestal.

In order to pull the cables through the lower guard, the pedestal was detached from the cockpit sole, which also required that the cover for the steering cables be removed to allow access for slacking the steering cables at the pulley wheel on top of the rudder post. One of the cable sheeves under the pedestal was also removed by pulling the cotter pin on one side to provide additional slack in the cable and provide more room for working the wiring connections.

A stiff wire was run from the new hole (either side) in the pedestal down to and around the outside of the aluminum shield at the bottom of the pedestal (to avoid being damaged by the movement of the steering cables). The cables (Power, NMEA, and SeaTalk) were taped to the guide wire and pulled to the bottom of the pedestal. The top of the guard was placed on the guard brace, the cables run through the guard brace, then through the lower guard, pulling the slack out of the cables so all the guard pieces were not yet mated but as close as possible. The lower guard was then mounted on the pedestal and the upper guard mated to the lower guard, through the brace, by inserting the upper guard into the lower guard and fastening the existing set screws. The 2 inches of cable slack, due to the insertion of the upper guard, could then be carefully pulled to the bottom of the pedestal.

Chartplotter mounted on angle guard

Wiring connections were made at the bottom of the pedestal for each of the cables using the provided scotch-loc connectors, or similar, and suitable cable purchased from the local marine store. The cables are run inside a cable protector to a small access hole on the starboard side of the cockpit steering cable recess, following the compass light wire. Reseal the hole after running the new cables through to the battery compartment. A wiring block was installed inside the battery compartment for convenient termination of the NMEA and SeaTalk bus connections.

The new Raystar GPS sensor is mounted on the stern rail with the new cable wire-tied to the post and entering the transom through a small hole used for the cable of the previous installation. The old GPS used a COAX cable and the new GPS uses the Raymarine SeaTalk bus, requiring the old cable to be replaced. The new cable runs to the wiring block where it is connected to the Chartplotter SeaTalk cable.

The installation is completed inside the cabin at the instrument panel. The old GPS-based instrument is removed, exposing the existing wiring. The power wires from the electrical panel circuit breaker (the old GPS used the LORAN breaker) are spliced onto a new power cable run from the electrical panel back to the battery compartment. The blank where the old GPS unit was removed is covered over with an appropriately stained 1/8 inch plywood panel.

Project Hardware
Navpod Angle Guard - AG10
Navpod precut For C-80 chartplotter - CP10RC
Navpod precut for 3 ST-60s - NP131RA
(we postponed the installation of the ST-60s while we accumulate more project money)
Power Cable – approximately 25 feet
NMEA/SeaTalk Cable – approximately 30 feet
White Silicon Caulk
Wire Connectors
Plywood cover for Nav Station panel

The completed project